PSU 1250w, 6 1070g1 or some 1070g1 and some 1080ti?

Now I have 1 GIGABYTE GEFORCE GTX1070 G1 GAMING GV-N1070G1 with 1 SEASONIC SS-1250XM X-1250. I plan t9 add 5 more cards. My psu is enough for 6 cards like the 1 I already have, but would it be enough if I wanted to substitute 1 or more 1070 with 1080ti?
Thank you!