Cathy - My daughter was in a huge wrap/cast for 8 weeks following a broken wrist 2 years ago. What we found for icing was 4 very large refreezable ice packs (10x14 or more) - alternately used and rechilled for at least 4 hours - we would wrap it around the cast, then wrap a hand towel over it to keep cold for as long as possible.
I also find comfort from the packs that come with my husband's meds - resting a wrapped joint on one, placing another on top and wrapping the whole in a towel.

I once asked a surgeon "How many orthopedic surgeries have you recovered from?" when he told me I was being a baby. The look on his face was priceless - but I thought he was going to throw me out of the hospital room. The nurse had to turn away so he wouldn't see her trying not to laugh!

Hang in there!
Sue