Same PSU I got on my machine. I'd change it to 750w if you REALLY didnt wanna wait, as my machine has been running really smoothly on the 850 and can't imagine the 750 would have any impact unless you were gonna push it heavily
You should have got watch dogs with the 3080? What CPU did you get?
A friend of mine got a new rig (not with a 3080) this week from PCS and no games, but contacted them as the CPU was the same as mine. They sent him AC Valhalla then.