I use the penny stove frequently in the dead of winter - it's a bit different than your whitebox but the same applies.

In the summer, I don't bother with a priming pan, I just fill and light normally. This doesn't
work so hot below about -10C.

In the winter I carry a small priming pan cut out of the bottom of a super size beer can. I carry the ready fuel in my pocket so it's not at -20C to begin with. I then fill stove, dribble a little bit (maybe 1/4 teaspoon) into the priming pan as well, and light the whole thing up. stove gets up and going real quick then. I have had good success with this down to close to -30C.

I typically only carry a 2oz nalgene in the pocket full of methyl hydrate in my front pocket, as usually in the winter I'm using an alky stove to heat up water for tea on a daytrip. If I'm camping where I'll be melting snow (most likely) I have a whisperloud or a svea with me.