They have emerged from the snowbank! (The weather decided to markedly warm up last week. We got rain. The snow pack has dramatically shrunk.)
Granted, they’re now encased in solid ice right under the covers, which isn’t great. It should be above freezing today, so I’m going to check them later to see if any melting is happening, and see what I can get rid of. If I do this again, won’t be using these containers.