Thanks for all the tips everyone. I left the bike in the truck last night and went out to start it this morning. Yesterday the temp guage said 12 degrees, this morning it said 28 and the bike started on the first kick, so it seems to only be a problem when it gets down to the low teens or more.
It might seem like overkill, but I've heard somebody on this forum say that they start their bike in their truck and let it idle until they're ready to unload. Probably not something I'd do unless there wasn't another way, but it's an idea.