Restore from icloud back up, how long does it take?

I got a new Ipad pro 2018 almost two weeks ago. Restored from an iCloud backup. It looks like everything is there, but there may be media (music, podcasets, videos) that i haven't checked yet.

Went to install the 12.3.1 update and was told it could not install until restore was complete!

What is going on?

The message said that any media not transferred will be lost if I quit the restore.

How long should this take? It is asleep, plugged in and connected to wifi for 6-8 hours every night. I dont see any activity indicating an ongoing restore. Nothing telling me estimated time to completion, etc.

Any advice greatly appreciated.