Sherwin Williams A-100 gloss…

Devoe Regency is a very good paint. Also an elastomeric coating would work great.

The paint isn't the real problem, any good paint will do a good job. The prep determines how well the paint does. I suspect the caulking will be the real weak link. Use a good urethane sealant as this will do the best with such temperature extremes.

Make sure the prep is done right and very good primer is used.

You mentioned that winters can get down to -30, A-100 is an excellent paint but will have to be painted above +30. I wanted to clear that up so there's no confusion.