I had this happen last night on the PS4. I normally don't use the rest mode, but after a recent system update that comes up as the default option when shutting down, and the load times are damn long, so I figured, why not.
I woke the PS4 from rest mode, and then ran around exploring and saving periodically - and eventually, on the outskirts of Novigrad, the game crapped out on me. I couldn't save manually, when I tried to load the most recent save it came up as corrupted, when I tried the second-latest save it got stuck reloading, and though I was able to shut the game down, my PS4 got stuck when I tried to reboot it and I had to do a reset to safe mode. (the "hold power button for 10s" kind)
I was able to load up the game after that, delete the corrupted save, and continue playing. (nervously saving even more often than usual, and periodically checking to see if the saves looked OK - the corrupted save was missing its thumbnail image, though I don't know how reliable an indicator that is) Got through 3 or 4 hours without incident. Read up on the problem a bit, saw that it seemed to be mostly an Xbox One issue but there were a couple of people who reported in on the PS4, and decided to just shut the game down and power down the PS4 this time... Hopefully that will be the end of it. Really hoping to get some gaming in this long weekend.
I retrospect, restarting the game from rest mode has been kind of wonky, at least a couple times - for example, when I started playing yesterday, I noticed that my character was wearing the wrong gear - the night before, the last thing I did was go through the inventory, switch a couple of items for slightly better ones, save, and log off - and now, I was wearing the old gear again. I'm pretty sure something similar happened once before. Despite that, I was able to play for a while and continue to save for a while, so I'm not sure if this is causation or correlation.