The 2 tree are in small 4" pots . Each tree is about 3' tall and since frost is maybe a month to month and a half away, I plan to overwinter them in pots in my storm cellar, but do I need to re-pot them to a larger pot before storing them before it frost . I'm in zone 6. I plan to set them under a shade tree, partial sun subdued light until I fear frost then move in. Cellar is dark and fairly temperature constant when it's cold outside. Also will they go dormant before frost and loose their leaves  or loose their leaves  after  frost.

I would examine the roots by lifting it out of the pots very carefully.  If they are root bound, I would go ahead and pot up to the next size.
As for the frost, it just depends how actively growing they are.  Frost may hit while it's still putting out new growth.  You can either bring them indoors on frosty nights if they're not fully hardened off, or let the frost kill the leaves for you.  I had a mix of trees that weren't dormant when the first frost came.  The leaves simply died and I pulled them off.  I place my trees in an unheated garage for the winter, and they all came back to life this year.