Best of luck to the OP!
I think Delta Airlines is the only one that explicitly (and recently!) say that when you pass away, your account/miles are dissolved.
I suggest the OP actually call each airline/hotel and ask for their policy. It might be a free transfer in this situation...
Also, I agree with the other poster who pointed out that certain airline/hotel website(s) don't give you the option of providing a credit card for taxes/fees that isn't in the acccount holder's name. In fact, I know for a fact that ICH/IHG (Holiday Inn/Intercontinental) always hold a reward stay reservation under the member's name. You can add secondary guests, but sometimes, it doesn't stick, and sometimes, the hotel doesn't read/recognize the secondary guest names, and may insist on the reservation holder be present to check-in. I've ran into this problem once before...My "secondary guest" had to have the hotel call the cellphone on record to reach me to confirm the reservation. Its rare, but these problems exist.