Thoughts on cold fermentation temps for a pale ale

Hi all,

Just finished my second brew, an American pale ale 2.5 gallon extract. OG about 1.0533. Anyway, I had to pitch a little high, around 78° unfortunately. I just couldn't get it lower in an ample amount of time quickly with the humidity lately. I recently purchased a insulated bag for fermentation and it is WAY more effected than anticipated. I left a few frozen 2 liters in it while at work today and came home to my thermo-strip reading about 58°F! I used safale us-05 dry yeast. My question is, should I lay off the frozen 2 liters and allow my temp to rise for the next few days? Considering I pitched high, the low temp now is concerning . Hopefully a good active ferm is raising the temp inside my vessel, inputs are appreciated!