In MN, have (3) 9x8 HAAS 2000 series insulated doors, in middle of winter with temps well below 0 the garage never gets below freezing (not heated); walls and ceiling insulated as well
I have repaired by cleaning out area and removing soft material that caused popout, then brush with concrete primer (bonding agent) and fill with a fairly dry mortar mixture
we have solid cedar beams for our entrance and used rymar extreme weather stain/sealer. It is excellent and should last several (they say 10) years. Sold at SW.
get shake and rake insulation
http://www.menards.com/main/building-materials/insulation/loose-fill-insulation/insulmax-reg-shake-and-rake-loose-fill-fiberglass-insulation/p-1444437002091-c-5777.htm?tid=-5989336962736742756