I decided to try painting the second color regardless of the temperature in the garage, which was about -1C when I started. The paint actually went on quite nicely, better than I had thought it would. Drying, on the other hand, meant a trip into the house where it was warm between coats!
The multiple coats brings up an issue I have--the new formula for Testors MM paints isn't nearly as nice as the old. This new stuff requires multiple light coats rather than being able to spray on one coat as with the old formula. It still works, but isn't nearly as convenient as the original MM. Hand brushing is also much, much more difficult with the new. I reckon they changed the formula for environmental reasons.
January Group Build - MiG-21