Strange thought that just popped into my head:
If Daenarys was killed by the walkers, would they be able to burn her body or would she still be fireproof?
I don't know where I read this, but I thought I read somewhere that Dany was only actually fireproof during the moment when the three eggs hatched in Drogo's funeral pyre. Otherwise, while she does exhibit extreme tolerances to heat and flame, she's not actually fireproof. Case in point, and I know the books are separate from the TV show, but when she escaped Meereen on Drogon to the Dothraki Sea during the coup attempt she actually was scorched. In fact, the "Unburnt" title would actually only refer to when she sat in the fire with the eggs.