For a few days I have managed to play several hours a night, no crashes as long as any time I had to pause I hit the PS button to return to the PS menu. If I left it paused in game it would crash.
Last couple of nights, it's crashed every hour or so at random points, again no discernable pattern. Oddly, I never have problems with driving, but it can happen at any other time. Most recently once while fighting some monsters on a hunt (halfway through fight), once while standing on a bridge for a photo op, and once back in Lestallum just after a checkpoint/cutscene.
Just have to remember to save frequently as I play, and I can work my way through.