Among the sights that can jolt us into memories of pre-Covid existence, the one that moves me whenever I pass it is a yellowing poster for Leopoldstadt. It had run for only a few weeks at Wyndham’s when the curtain descended, and the poster looks a bit like one of those discarded props that dates a crucial moment. One week, the theatre was fêting a Tom Stoppard swansong, recovering (barely) from the electric shock of Brexit and chasing the next big-screen catch to lure global audiences. The next, theatregoers (which turns out to be around 40 per cent of us) have to sate our dramatic desires by streaming productions. This is about as satisfactory as online dating as opposed to the real thing. Or so I am told.

What will it take to bring live theatre back after a long, barren summer of silent stages, empty rehearsal rooms and playhouse bank accounts tumbling into the red? Up to two-thirds of companies face what Sonia Friedman, the prolific West End producer, calls “a complete obliteration”.

Uncommonly, given theatreland’s propensity to hyperbole, this is a statement of raw fact. Theatre relies on the new blood of productions to drive bookings and revenue. Its costs mount even in the mothball era: it costs £30,000 a month to keep a West End playhouse shuttered, while a complex of the National’s size is losing millions by the month.

Because stage funding is a complex web of commercial enterprise, state subsidy (for some) and foundation and charitable, even going bust is not simple. “It would take months to wind up a big company,” one financial backer tells me. That puts pressure on those in charge of companies to plan for the worst outcome at the same time as scrabbling for rescue packages.

Time is of the essence. Best be pragmatic however: many smaller theatres will not come back from this crisis in their old form or will have to merge to have any chance of survival. Touring will be devilishly hard — tough on the already underserved regions — and programming will be limited by many irksome practicalities.

Great niche theatres like the Young Vic, but also the big venues such as the Old Vic and Globe which depend heavily on tourist bookings, will need urgent help. The new Culture Secretary, Oliver Dowden (who does at least sound as if he genuinely relishes the arts), has assembled an Entertainment and Events working group of producers and key admin folk to liaise with Public Health England.

Theatre simply cannot work on the social distancing arrangements of two-metre alienation from each other

But the big decisions will in the end land with politicians, as they have elsewhere in the crisis when it comes to allowing risk to proceed in order to protect a social good. Wisely, the working group has set out its stall not only with a plea for funding to tide over rocky businesses, but with an aim of securing a major policy change which would make the most difference to bringing back live performances. The gap between success and failure is around one metre.

Theatre simply cannot work on the social distancing arrangements of two-metre alienation from each other. There is no outcome on these terms which would leave playhouses remotely viable. So the sector will petition government for a reduction in distancing guidelines — not uncontroversially, since any degree of proximity must raise the risk of infection as long as the virus persists, and audiences skew towards older people who are more vulnerable to infection.

But as a member of the working group points out, the rule is elastic anyway when big national and commercial interests are at stake. If airlines can operate on the principle that passengers can wear masks and sit in strict rows (less likely to carry infection than seats in curves), then theatres should be given a chance to work on the same principle and figure out best practice as they go along.

I am not so convinced by the writer James Graham’s reasoning that any money spent to rescue theatre will neatly flow back into the Treasury in tax revenues. The claim that expenditure “will pay for itself” is always a bit suspect. The overall pulling power of the theatre, including for restaurants and nightlife, has added up to an estimated £2 billion in revenue for London’s coffers.

But that only comes good if entertainment and travel patterns settle quickly and there is no second spike of the virus. The real calculation is likely to be a serious subsidy commitment. But saving the best of our theatre human resources, technical know-how and infrastructure is a long-term bet we should take.

There are also reasons to be optimistic that curtains will rise again before too long. Andrew Lloyd Webber thinks the South Korean model of tracking and tracing, temperature testing and compulsory masks could work and is offering his Palladium venue as a possible test site in the early autumn. It conjures up the odd thought of torch songs being belted out by lovers several feet apart.

A bit of lateral thinking should help rescue the stage after 2020’s brutal interval

But the nimble Shakespeare parody Upstart Crow on the BBC reminds us that if the theatre could manage with men playing women’s parts until the Restoration, a bit of lateral thinking and experimentation should help rescue the stage after the brutally unscheduled interval of 2020.

Until then, we have Hamilton (streaming for the first time with Lin Manuel Miranda in the cast on Disney+ in early July) and the back catalogue of the theatres on YouTube. You do need to fish around around for the good stuff: Tom Hiddleston’s thoroughly bloody Coriolanus and James Graham’s This House work well enough on your flat screen. “Theatre is always with us,” as Lloyd Webber put it in one of his peppy introductions to streaming musicals. (If you can get through Cats without a lot of wine, good luck to you.)

Like Samuel Pepys, relishing his first outing to the theatre after the Great Plague, I miss the serendipity of the craft and never really knowing whether I will love or loathe what happens when the curtain goes up. His first outing when theatre resumed in late 1666 after the Great Plague was to The Maid’s Tragedy by Beaumont and Fletcher, a tangled melodrama which the diarist, venturing back to the stalls with a heavy cold, did not much like: “The whole thing done ill and being ill also, I had no manner of pleasure in it.” Bloody critics — never happy. But the show will go on again; it always does.