Hey Flagler,
Got a two car garage layout here.
It was 106 outside today, winter typically falls into the 20's only for a very short duration. The garage follows the rest of the house (70-80 deg) with climate control via forced air HVAC. The central air provides positive pressure to the garage which helps with dust control based on location of return air. I insulated the walls and hard lid, added an insulated roll up door, and have a backup portable a/c unit for ops sess. I used the roll up door for access to get garden tools for years with minimal concern (they are in a shed out back now), and the garage has / has had, less dust build up compared to the rest of the house.
Only issue I have had was one hot week the a/c system failed for a number of days, the garage made it into the 90's, and I had some minor trackage issues. Out here in So Cal, I have seen two other layouts that the rails were ripped out of the plastic ties on semi-tight radius corners, one during an excessive summer heat wave, the other on a rare cold winter night... both issues adjacent to uninsulated garage doors (don't know what the humidity was).
Jeff
http://espeeoregondivision.blogspot.com/