But you had it in the cold for longer than you have had it above 70, that's part of the delay. In fact if it was that cold in the garage you might as well just consider that your beer has been carbing only as long as it's warmed up to above 70, your yeast was asleep in the garage so it didn't do anything towards carbing. And it probably needed a few more days just to wake up when you brought it inside.
Also Realizing that with bigger beers it takes longer for them to carb and condition. The
3 weeks at 70 degrees, that we recommend is the
minimum time it takes for average gravity beers to carbonate and condition. Higher grav beers take longer.
Stouts and porters have taken me between 6 and 8 weeks to carb up..
I have a 1.090 Belgian strong that took three months to carb up.
Temp and gravity are the two factors that contribute to the time it takes to carb beer. But if a beer's not ready yet, or seems low carbed, and you added the right amount of sugar to it, then it's not stalled,
it's just not time yet.
Everything you need to know about carbing and conditioning, can be found here
Of Patience and Bottle Conditioning. With emphasis on the word,
"patience."
Read the above blog, and come back to the beer in a couple more weeks.
If a beer isn't carbed by "x number of weeks" you just have to give them ore time. If you added your sugar, then the beer will carb up eventually, it's really a foolroof process. All beers will carb up eventually. A lot of new brewers think they have to "troubleshoot" a bottling issue, when there really is none, the beer knows how to carb itself. In fact if you run beersmiths carbing calculator, some lower grav beers don't even require additional sugar to reach their minimum level of carbonation. Just time.
Lazy Llama came up with a handy dandy chart to determine how long something takes in brewing, whether it's fermentation, carbonation, bottle conditioning....
I would agitate the bottles to help re-suspend the yeast. And just give it as long as it takes....it'll carb up
eventually.