Propane and regulator freezing up is usually because of lack of pressure in tanks in extreme cold weather. When cold, liquid propane gets into system instead of vapor causing many issues (regulator freeze up, regulator not reducing pressure properly) This could be dangerous. If you put a magnetic oil pan style heater on the lower side of the propane tank (being careful that you are away from the rubber propane line) then you probably wont have an issue. Also using an automatic regulator : Turn both tanks on slowly (pressure needs to equalize in system or safety valve in green nut hose area will limit the propane flow) & put regulator indicator lever toward the tank you are using. When it gets empty it will automatically switch to the opposite tank and the indicater on the regulater will turn red indicating that the tank it is pointing to is empty.(if cold sometimes will not show properly). Turn the indicator to the oppisite tank and it show green again. you can then remove the empty tank and get it filled.(sometimes the check valve in the regulater will let a small amount of gas seep out of the empty tank hose so use caution or turn off all propane and get filled)