They should still be okay so long as they didn't completely totally freeze solid in the hips.

Well, I harvested them and planted them the day after I posted this. So far, no signs of life, but I suppose it's too soon.

Many, if not most, rose seeds need stratification, that is, subjugation to cold for a period of time, usually at least a month or so before they will sprout.
The article should help.
Steve.

Here is a link that might be useful: Growing Roses from Seeds