I would go with Tales from the Yawning portal. Do it Black Mirror meets Sherlock. 1 season only. Each episode 75 minutes long and it covers one of the dungeons. Use Yawning portal inn as center piece and framing device, with groups of adventurers recounting their wildest adventures.
Anything with more than one season risks being cancelled before proper plot even starts to roll. Unless it's hypothetical where it's up front multi season show that shoots in one go, i would rather have solid anthology of loosely connected stories. It also gives it higher re-watch value.