Your only choice is Active DP to DVI-D connectors. And with them they will only overclock to 75hz.
Im only using 1 screen now after getting my 1080ti.
Was driving 2 fine on my 980ti but it had 2X DVI-D
SLI Voodoo 2 - > GeForce4 MX 420 -> GF 6600GT -> GF 6800GT -> GF 8800Ultra -> AMD 4870 -> AMD 4890 -> CF AMD 5820 -> CF AMD 6850 -> CF AMD 7970 -> SLI GF 680 -> SLI GF 780 -> CF AMD 290X -> GF 980ti -> SLI GF 980ti -> GF 1080ti -> SLI GF 1080ti -> <- RTX 2080ti (DOA/Refunded)