I was thinking about the same "problem" today. I have two of those little beer insulating huggie holders, so I'm limited to two beers.
Since my tub is indoors, the only snow I can bury my brewskies in will be inside a cooler.
My idea was to find a foldable "TV"- tray like table, placed next to the tub, that would bring the top of a cooler to the same height as the top of the tub.
Big table = big cooler.
I use two of these tables on my RV, I'll have to check out if they are high enough. If so, other places like WalMart may sell them.
http://www.campingworld.com/browse/products/index.cfm?deptID=&subOf=4&prodID=4496&src=TSC