When inspecting hives we should be looking for mites on drone larvae. What would be considered a proper sample size and a mite count that would trigger treating?

Getting lost on all the on line advice for winter hive venting. Plan on using candy boards and insulated top cover. For this area what is the best method to minimize condensation during winter?

I wanted to use formic Pro as a fall mite treatment but the temperatures seemed too hot so I used Apivar instead. Apivar Strips are scheduled to come off on Monday. Since the queens are shutting can I get a meaning full mite count? I plan to do an Oxalic acid vaporization in Late November or early December as a final clean up for the year, so should I even worry about a trying to get an accurate count now?

hives are going thru 2 quarts of sugar water daily. Should I keep feeding this amount during this heat wave or cut back so the bees dont over fill the hive