For various magical reasons, a particular area of my world spent roughly 100 years under an average of 10m of ice (3 - 15m of compacted snow). Unlike a conventional glacier, this was stationary. Snow fell effectively uniformly (or close enough for this question) and just did not melt. The average temperature (year round) hovered slightly below freezing. Roughly 100 years later, the magical source was removed and a reverse effect caused it to melt off. This question doesn't care about the effects of the melting--that's already handled.
Before this happened, the area had been inhabited by a group of people who built in (reinforced) stone and other cold-weather-adapted styles, with buildings mostly 1-2 stories but occasionally as much as 4. Due to magic, their buildings had roughly equivalent physical strength/durability to modern reinforced concrete, but with much less use of glass and steel. For the purposes of the question, you can consider them to be effectively concrete. The people themselves left the area as the endless winter substantially set in, with time to do what they could with tools at hand to "winterize" the structures.
How much damage would have those structures and their contents have sustained? Total destruction (collapse)? Destruction of fragile materials (glass windows, contents susceptible to water damage, etc) but generally intact? Something else entirely?
I expect that underground things like cellars and underground vaults would be basically fine as long as they weren't exposed to the cold and moisture, while there wouldn't be tons left of the contents of surface buildings unless those were relatively durable (so statues maybe, books no). I'm less comfortable about making predictions about the structures themselves.
Notes: The magic used to reinforce the materials can be treated as simply a durability enhancement to reach roughly modern standards. Natural weathering other than the ice itself would be nice to know, but is secondary. Weathering from other sources (such as creatures) can be ignored.