You could probably push them to 220-230 watts or so without issue.
3 x 850 and a single 1000 (use the bigger supply to run 3 cards and the MB/RAM/etc) should be plenty.
4 cards even at 250 watts TDP (which is a waste, 1080 ti hashrate at 250 isn't enough higher than at 225 to justify it even on GOOD cards like the AORUS) will run comfortably on a 1200-1300 watt supply.
3xEVGA G2 1300 (or 3 x Seasonic X-1250 IF you could find them any more) would be viable for a 4-card per PS setup - and if you use the B250 Mining Expert motherboard, you don't need Add2PSU for that configuration (but that MB HAS been hard to find for a little while).
Thanks for the help.
I didnt know about the B250 Mining Expert, found one available and already ordered it.
I will use 3x Corsair 1200W Platinum HX1200i. I think it should be fine, right?