I will do oil changes on hard pack snow and have done them in -20C, prefer about -10C on a winter change. Hard pack pure white snow is great for checking for leaks later, NO dust either. No ice/snow melting and dripping all over me and work area. I go to great lengths to securely block tires.
Like summer oil change I put down a sheet of plywood to lay on, filter is warm taking it off, pan is warm, engine warm, the oil draining is warm. I keep new filter, tools and oil inside warm porch close by.
Short spurts of time on each phase of oil change, dont really get cold at any time. Organization is everything, do all prep work and no reason to cold. Cold doesn't bother me though, I used to walk a 20 mile trap line in -50F up north when I was a kid. Oil Change is moderate for me in sub zero.
I haven't built my garage yet, I will NOT have anyone else change oil on my vehicles, NEVER, I would rather do it out side in -55F than trust anyone else, I get long winters here so gotta do what I gotta do in maintenance.
Cyprs