I will not charter a boat without AC, but we have only done 1-week trips in the past, one in November and one in April. On the April trip, we lost our cabin AC (but had it in the salon and slept with the door open) but managed okay because it was dry and we also had the breeze from the hatches.

We have family chartering a 2nd boat and we are doing a mini floatilla on our upcoming trip. They do not have AC. I am genuinely curious to see if one or two of them wind up sleeping in our salon.