I grew up in Edmonton, moved west 22 years ago. I have completed 5 Festive 500s out here in the greater Vancouver area. Some of the days required riding in some pretty grim weather: 2-4 C and cold cold rain. I cannot imagine trying to pull one of these off outdoors in an Albertan winter. I used to ride the MTB in the River Valley up to about -15 C and honestly about 90 minutes was enough for me. Road riding was off the table in deep winter.
But doing this indoors, well, kudos to you if you get it done. In terms of strategy I can only say doing over the entire 8 day period with shorter rides feels like death by 1000 cuts for an outdoor version. My best memories are from cracking it out in 4 days straight, but that was a decent year weather wise and I was 46 at the time. For indoor, I feel like sanity might require a 7 or 8 day strategy. Good luck, and hope things warm up a bit for you to get in some outdoor activity as well!