I most respectfully disagree..
If it had been one regurge, I could see waiting it out...
But we are talking about 3 regurges in a row. The last one AFTER a long break and nutribac.
Could it all still be related to the drafts and cold ? Perhaps. But 3 regurges in a row would make me nervous enough to not waste anymore time and see the vet stat. If nothing else, to at least rule out some stuff, and possibly get some treatment done (Nutribac paste??)
I know the timing is bad, and Vet visits can get expensive. However, 3 regurges can set the snake up for a chronic cycle that doesn't end well. Not even just from the original cause, but simply from the damage that is done to its system.
Ultimately, its always up to the owner, though. They know their snake best and they know how far they can take it, financially.
I do hope it all ends well !!