my 10 gal trees got total of 16 oz. of water each last yr in my garage. i'm sure that's not typical, and i'm sure i under watered it. i was neglecting the trees last winter due to personal illness. but they made it.
on the other hand, all my 1 gal trees died. they got some water at the beginning of the winter like the big 'uns. and rest of the winter, didn't get a drop.
this year, i watered them heavy before putting them into the garage, 1 gal pots that is. my 10 gal pots are still out in the deck. my 3 gal is in the garage since last night was near 35. when the temp hits 32, my 10 gal will go into garage.