I'm curious if anybody has a more "self-hosted" solution, but I use burner numbers through the MySudo app and simply delete the number and buy a new one every few months.
If you look up Michael Bazell, he has a strategy for bulk buying voip numbers by tricking voip providers into believing you're a large established business. You could buy dozens of numbers and just cycle through them. But that method requires a lot of work and social engineering and the providers are becoming privy to those tactics.