Since people are sharing their playlists, here are a few that I put together and rotate between:

25h+ spacey ambient, very relaxed, almost but not entirely without words

https://open.spotify.com/playlist/0tLvg6WcRMc8bn8McRfruK?si=...

12h+ downtempo, no vocals

https://open.spotify.com/playlist/77rLJZoIo7VYjrHWk2gKc7?si=...

7h+ melodic post rock, no vocals

https://open.spotify.com/playlist/6DWXAfI1IPtzIVTXcBd1bU?si=...