I doubt it's the cold. I've had 10 & 20 lb tanks sitting on the ice outside my fish house when it's as cold as -20 with no problems.
I use the same heater in the off the bottle-cooker configuration. This one here:
http://www.buy.com/prod/mr-heater-mh...203529894.html
Only I use an 8 foot hose to the heater to a 20lb tank rather than a small disposable bottle. In 20 years of use there's been roughly zero issues with it. But if I had to make a first guess as to what's up with yours, I'd think a plugged orifice or a problem in the regulator.
http://www.propaneproducts.com/paulin-parts.html