I too have ditched Sky this year and I have just read all of this thread with surprise that there was no mention of MythTV, especially on a Geeks' forum.
MythTV has every PVR feature you could think of. I have my MythTV "backend" in my garage.
Scattered around the house, my "frontends" are 2 x FireTVs, 1 x Nexus Player, 1 x Intel NUC and 1 x HTPC
All of the frontends use Kodi for MythTV and local (on my server) content. The NUC and HTPC use LibreELEC (Just enough OS for Kodi)
The FireTVs and Nexus Player also play Netflix and You Tube (and some other stuff)
Note: The MythTV backend is the only device which requires an element of Geekiness but the journey is worth it to have such a versatile and flexible system.