Or does it need to be a 10 frame to allow for more space? I was thinking about trying my next hive with a single brood chamber but all I have at the moment is 8 frame hives.
4 over 4 is not 8 side by side. the volume is less of an issue that the comb depth IMO, here in mich 12-18 inches is the least I would consider.8 will even work depending on the configuration. I overwintered a mid August swarm in a 4 over 4 resource hive in 6a. No room for error though. They must have at least 3 frames of honey overhead, insulation and fondant in my opinion.
I have huge respect for Paul and love his videos, but Paul's climate is a lot colder than mine. The warmer climate means bees are more active here in the winter yet its way too cold for forage, which means they eat more of their stored food. In an 8 frame configuration, if we have a cool spring then they'll need most of 16 deep frames, with the second box completely full and a well established honey dome in the first box, to make it to the flow. This year their stores easily got them there. Last year it snowed till June, and they needed a lot of help from sugar. That underscores why beekeeping is regional and is why I use single brood chamber only part of the year, mainly to force them to completely fill the second box.