Winters, for a hibernating marmot, can be hard in several ways. If they're too long, animals may burn too much fat and starve. If they're too cold, animals may burn too much fat and freeze.
This winter, coming after one of the longest and most snowy winters on record, is looking quite interesting in that there is very little snow. Snow is a blanket, for marmots, and insulates their burrows. While there is some snow, there's not a lot of snow and that blanket may be a bit on the thin side.
We'll have to wait for May to find out for sure.