I haven't donated, but I've been (slowly) transferring my points to Accor. Not the easiest process, but even one transfer (2500 -> 500) does lengthen your expiration date by two years. Frankly, I'm trying to just convert them all and be done, but there's a max of 25K per year. And Accor points expire in a year. So early next Jan I need to transfer the rest (I assume this will reset the expiration on my existing Accor points, but this is my first use of that program).