I just can't see large gatherings anywhere in the world until there's a vaccine. That would be fall 2021. Ish. So, all sports of any scope will have to determine the economics of trying to continue.
So far the only sport I have read about that's optimistic is curling. They have sketched out how they can run it and it sounds reasonable. Haven't heard of any others with decent prospects.
I can envision a scenario, though, where before the end of this year we reboot significantly across the world but with heavy heavy restrictions placed on human interaction. That could look like anything such as a max number of people in any venue including even small social venues like restaurants, with social distancing part of the protocol. This could also mean international flights restored before the end of the year. Not saying that happens but I see the potential for it, with well-planned controls.
That to me says the earliest skaters can get onto the ice would be fall (Oct-Nov). If the season happens at all, I see all fall events cancelled, and if there is no serious resurgence of the situation over the winter, we might see national championships happening anywhere from Jan-March, no 4CC or Euros and go straight to World's in the March-May time frame. No touring, of course, so it can be pushed as long as ice is available.
I see that as best case, providing the situation in most of the ISU nations permits this level of restoration on this timing. Spitballing, I give it a 30-50% chance. Unless we see every country on the serious decline in the summer, then everything I said is likely already in jeopardy, so forget it.
The worst case scenario is Beijing is delayed or cancelled. Widespread availability of a vaccine on a normal timeline is very late 2021 and possibly into 2022 in some countries. Restoring sports fully at that time just does not allow enough time to train and qualify countries and athletes for the Olympics. Let's hope it doesn't come to that.