Re: Down with Double Deeps! Fess up, you alternative hive-style followers!!!!
8 frames would be fine for winter in your climate but spring buildup would require some adaptations such as giving a couple of supers above an excluder to keep the queen in the deep frames while providing space for excess bees to cluster. It would not be a problem otherwise. I would not use 8 frames with Italians, but with Buckfast or with Carniolans, it would work.
I use 32 mm frames which would allow 9 frames in an 8 frame box. I marginally recommend the 32 mm frames with a caveat that aggressive spring management is needed to prevent swarming.
I will extend this a bit by saying that the square Dadant hive configuration is used because it facilitates several management options that are not available with rectangular equipment. It is also a size that conveniently handles spring buildup without having to add space until honey supers are needed. My spring management is two things, making sure the bees have enough stores to get through to the flow and making splits from the strongest colonies to prevent swarming. The splits often make enough honey to have a bit of surplus.
NW Alabama, 50 years, 20 colonies and growing, sideliner, treatment free since 2005, 14 frame square Dadant broodnest