In reply to martinturner:
I have a Luxe Outdoor "copy" of the Hubba Hubba, and it is a very breezy tent inside. The inner is mostly mesh, doesn't retain warm air, and lets breezes through. Great for what I bought it for, summer canoe camping where there are mozzies or midges, and free standing for camping where pegs are difficult to use, but in winter I have to up-spec what sleeping bag I use. Its also a bugger to get out of the sleeping bag in the morning as the tent feels so cold! The slightly curved ends to the flysheet don't help.
On the other hand, in summer its a delight to use, when others are sweltering. Its also great that can be pitched inner or outer only, and weighs very little for a free standing 2 (friendly) person tent.
The other factor will be that the smaller the tent, the warmer it will keep you as there's less trapped air for your body heat to warm. The Hubba Hubba's generous porches and the fact its a two-person tent won't be helping.