Just like the others: No problem in the winter cold with my VLX.
I start it with the choke on, let it warm up, and off I go.
It may run a bit rough at first when it's cold and I'll leave the choke on for a block or so...just to the end of my street...but them I'm good to go.
One thing I've noticed: It get's going a lot more smoothy after the valves are adjusted. If I recall, it's supposed to be done, by the book, every 8K miles.
I usually go over that a bit and have the adjustment done once per year during late winter/early spring when the dealer is not backed up. Then I know I'm good for the summer.
When I bring it back home after the adjustment, it starts and run noticeably smoother.
Have you been keeping up with the valve adjustments?