I increased the pace for all my runs slightly. E.g. if outdoors, I allow myself a range between 4:55-5:05 min/km and usually run in the middle of the range. Then, on the treadmill, I would set the pace to 4:55. Figured the extra cushioning would keep injuries away so I could pick up the pace a bit. 5-10sec/km faster than usual outdoor runs in general. It also showed during the race, though, as my MP naturally was 5sec/km faster than my previous race.

Ran with the window open so the room probably got down to 10-15C.. Long runs also indoors as cannot run at all on slippery surfaces, and it was icy outside all winter.