Low pressure propane tank

If you are having problems in Cypress, or thereabouts, I don't think temperature is your problem, it just doesn't get that cold in our area. I'd be inclined to replace the regulator - they are cheap and if it doesn't fix the problem you'll have a spare for when it does fail.

Oh! I forgot! Try cracking the valve on the tank very slowly and see if that fixes it. This new fangled stuff has valves that sense high flow and sometimes shut down if the valve is opened too fast.