I would not try drilling out the gas ports. Since this only happens in extremely cold weather, I suspect it's a viscosity issue with your oil. If you know you will be shooting in extremely cold weather, thoroughly clean the gun beforehand of all oil, and then "lube" with Militec-1 (a dry lube). You can go back to lightly lubing with a traditional oil when it warms up.
"I would rather be exposed to the inconveniences attending too much liberty than those attending too small a degree of it."
"It behooves every man who values liberty of conscience for himself, to resist invasions of it in the case of others: or their case may, by change of circumstances, become his own."
"Government is ... force. Like fire it is a dangerous servant and a fearful master..."