Lived with cold weather for 38 years now, and even at the -51 i was in a few weeks back i've never had an air leak. For an alloy rim to get cold enough to shrink to the point it shrinks and causes air loss you'd be looking at the -180 to -200 range. the biggest concern i have in cold weather is the tire freezing, creating a flat spot where it was parked.

08' Jeep Wrangler
64' Plymouth Sport Fury 383
58' Triumph TR-3A