There are quite a few companies that include Covid cover if you buy a holiday with them and most travel insurance policies will include both ski cover and Covid.
However, it may be tricky to find a policy that will also cover you if you travel to a destination that the Foreign Office is advising against travel there.
Both Voyager Insurance’s High Risk policy and BattleFace travel insurance do have a policy that covers you for this but there may be limitations.
As things change daily during these Covid times, it’s probably best to book a ski holiday that comes with flexible booking options. This will mean you have help if the resort has to close, you’d have financial protection and help to get home.
Incidentally, if you have an EHIC card, this would offer you cover for illness in the same way locals would. This expires on December 31, however, if you travel before that date and stay into the new year, the government says this card will still be valid for use.