There's a lot of factors here. If there's disease involved, your chances....whatever they are....drop dramatically. I assume that you are attributing the death to heat / handling / shipment time. If that's the case and your remaining bees are otherwise healthy I would say that your chances are pretty good. Adding a frame of brood and even shaking some nurse bees in will raise your odds a fair amount. You really want to get enough bees to cover brood and if you can feed, you'll artificially increase the efficiency of the field bees. I know you said that you saw no obvious disease or pests but it's hard to rule out everything. Keep a close on on them as they build up!