I've tried this and it took ~5 minutes to generate 10 seconds of studio on my 3080. That just doesn't work if you're trying to generate an hour long podcast.

Also there's this which offers a speedup to normal tortoise: https://github.com/152334H/tortoise-tts-fast

That sounds way too slow, just go with lowest or the second lowest quality. I think even the lowest quality works just as well.

Also you can rent a GPU on vastai or runpod, go with 3090 which should cost like 0.29 or even 0.15 if you go with spot pods.