azazel....when you said at '5% ACV' do you mean your current hydrometer reading is around SG of 1.035 or so, or that there has only been a SG decrease of about 0.035 in five months???
What was your actual original gravity (assume close to 1.180) and what is SG now?
Not sure what must temp was when you pitched yeast, or max temp exposed to...but the few days at 55F just slowed things down. Seems like now the must may be at room temp, what is temp, so the yeasts are at work based off action you describe...but needs to be confirmed with decrease in SG (since bubbles are not always a true indicator of fermentation). If any yeast survived the initial hot spot they are likely reproducing, but nutrient component can impact that. All the sugar you need to make alcohol is on board, the yeast just need to do their thing.
Motto: quel che sara sara