I bottled my American IPA about 3 weeks ago and used about 4 oz of dextrose for the 4 gallon batch. The main problem is that the temperature has varied a Lot while I was gone. The temp varied in storage from 33-72 degF with an average temp of about 50. Now these beers are flat and I was wondering if warming them up and letting them sit a few more weeks would allow them to carbonate or is the yeast already dead/ inactive? Also the 4oz/4gal of priming sugar to beer is a little high for this style but I was hoping that could possibly help me in this case. Also I heard about possibly using dry ice? Or I have yeast that I originally washed from this exact batch. Should I use that somehow? Any suggestions are appreciated.