gently scrape away the bark on a branch or two, and if it is a normal looking bright green underneath the outer bark, the branch, and the tree is probably still alive. If it is only brown, or an even less attractive brown, it is likely dead.
Wait until you see activity in the landscape. Repot when your local landscape maples have their buds open and leaves about 25 to 50 % unfurled, at this point you probably won't have a late freeze. Then it is time to repot. At that time you should see buds on the azalea or Rhododendron expanding. If there is no change in the bush, it is likely dead.