I'm in Delta Junction, a little south of Fairbanks. Yes, use an oil pan heater on your automatic. We all do that up here, because our transmissions last longer that way. I used to do it on my manual gear boxes, too, before the synthetic gear lubes came along. Also consider a synthetic ATF.
One morning 30 years ago I was driving in to work in a two-ton Chevy, and I tried to shift the two speed differential. It was about -40, and the stinking thing was too stiff to shift ... I was coasting, couldn't get into gear. I got lucky and it eventually went back into the other position, so I didn't need a tow. I bought silicone heat pads for every gear box that shifts after that. My modern gear boxes from the '80s use synthetic ATF, so the situation is less dire now.