If your boat is trapped in pack ice, I'd say prep for loss of the boat, but stay with it until it actually happens.
If your boat is trapped in fast ice, that is you are in a small bay and the water freezes around you, you may be just fine depending on the boat and construction.
Several
books to consider:
Time on Ice: A Winter Voyage to Antarctica by
Deborah Shapiro and Rolf Bjelke (Oct 9, 1999)
Between Two Poles - Hardcover (July 27, 1995) by
Amyr Klink and Lucia Villares
'Bowditch', aka 'The American Practical Navigator' has a fairly serious section on ice issues.
Also 'Icebird' by David Lewis, but I don't
recall him covering much if anything in the way of being icebound.