I read that Supergirl's second season is a full 22 episodes. I think it will keep the Monday at 8 slot because Monday nights have been a ratings black hole for the CW and if Supergirl pulls anything close to what it did on CBS it would be fantastic by CW standards. And then you have a DC show Monday-Thursday straight across (although I'm sure Legends of Tomorrow will remain a midseason show). Supergirl will also be getting budget cuts next season. It's moving filming to Vancouver from LA, which will save money and should facilitate more crossovers with the rest of the Arrowverse. However we'll probably see some trimming of the cast too. I'm nervous for Martian Manhunter, we probably won't see him transform much. But he'd be great leading a team on Legends of Tomorrow!