" I like to leave two full medium supers for each hive to overwinter. I would also like to be able to treat with OA in December, "

I do not see the problem with just treating in Dec with the supers on the hive.  If the hive is at all strong in my experience there would be very little honey left in those two supers by spring in my climate in NE Ohio.  You do not say where you live.  If you live where there would be lots of honey left by spring why leave so much?  You are not supposed to harvest honey from supers after the hive has been treated with oxalic acid.  But, leaving it for the bees to eat is perfectly ok.  After all, honey naturally has some oxalic acid in it even with no treatments at all.

Dick

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html