Originally Posted by DMPHL

If you're not particularly committed to using them on yourself (which you may be, and no shame in that!), and are so inclined, you could donate them. I had a similar stash of leftover Avios, and signed up with Miles4Migrants, which relies on people using some of their extra FF miles to pay for travel for migrants, refugees, etc. in not-so-great political circumstances, and who cannot afford the flight. My miles went to reunite a young woman from Sudan with her family in Europe.