I generally don't need to run my wood stove for more than 6-7 hours at a time... but had it going for 30 hrs+ straight from Friday through yesterday evening. We hit -21.5 Sat AM, only got up to +1.5 around 1430 here.
Yes, the suddenness of it was hard; I've been in temps that low (and lower) before, and for extended periods of time (10 days+), but not immediately after a consistent run of temps around freezing!
Did you happen to see the story about the new record on Mt Washington? Apparently, the stratosphere is normally 4-12 MILES above the earth, but yesterday's polar vortex brought it down to around 4000 FEET in NH. Mt Washington, at 6288 ft, actually had its summit IN THE STRATOSPHERE yesterday. Winds over 100mph, temp around -48. Wind chill calculated to be -108F, apparently a new record. Guess that's why, at about 50 miles SE of Mt Washington and at 1500', we had those wicked winds and low temps all day.... It was just plain miserable outside.