I winter my suber either indoors or in the garage. They do well in either location...even with the reduced light. My indoor ones have been warm enough (65F) to flush during the winter. Those leaves tend to be huge due to the lesser light. The garage kept trees seem to go dormant (~40F-50F) and do not flush.
The garage wintered ones do drop some leaves and do have so twigs die back. Not a problem when growing out. I can see it being annoying during development.
My experience anyway...yours may vary.
As far as ramification reducing leaf size? Well, certainly for swamp oak, ramification could not hurt!
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This is a sample leaf off a nursery purchased tree that I trunk chopped this spring. The tree sprouted several new buds...two of them have grown to almost 6' so far. All the leaves on those two branches are about this big! I've got many years yet before I get to a 4th level of ramification
But yes, be aware that oaks can have very large leaves until they ramify!