Gas and Oil Home Heating Furnaces - Propane furnace

I went up to my cottage for the first time in the winter last weekend in northern Ontario Canada. When I arrived, it was -22 degrees Celsius in the cottage. When I attempted to fire up the high efficiency propane furnace it only ran for 5 to 8 minutes and then the heat stopped, but the fan continued to run. The gas tank is large and was full.
I attempted to reset and start the furnace to no avail. Did the cold temperature in the cottage cause the gas valve (on the furnace) to freeze, or did the gas in the plastic underground line from the tank to the furnace freeze up?
Would I have had the same problem if I kept a portable heater in the furnace room to maintain a temp just above zero?

if the valve initially opened, in my opinion it would "freeze" that way, not shut. look for loss of voltage to the valve, psi switch dropping out due to possible heavy load (cold flue) etc. not sure that freezing gas line is the cause. disconnect line after shutoff, turn on, any gas? sounds like a furnace problem to me. got plenty of airflow? your limit switches may be getting out of whack due to such severe cold.......have not seen minus 22 C since i moved to georgia:D