I use 1 inch fome insulation on the outside of the hive. also a larger piece of 1" fome on the top, big enough to make a drip edge away from the hive.
I also put a 1/2 inch thick piece of fome in the telescoping cover to add extra insulation.
I do not block the ventilating holes at the top of the hive.
I can still get into the top of the hive if I need to.
A piece of 4 foot by 8 foot fome insulation is about 15 dollars at any home improvment store.
Good luck Jerry
My pic didn't load. I will try again
Something like this??
(http://home.comcast.net/~k_haas/home/hivewrap.JPG)
I have an empty medium on top filled with insulation too.
.
You should consider to by some polystyre boxes use as broods and compare how they work in you systems.
I use 2 inch foam insulation here in MT. I tried to tape the corners of the insulatin last year but that didn't stay together well. This year I used 2.5 inch screws with a large washer. I screwed the foam to the supers with 2 screws per side.
//(http://[ftp][/ftp%5D)