I maintain my Diamond status through accumulated points each year rather than nights. Right now I am at 42 nights and 152K base points because my stays are typically $350/night. Roughly $15k in spending, about $5k over what it typically takes to make diamond.
That said 80 nights is impossible for me unless I give up my Marriott Platinum status and there is nothing at Hilton that would make me do that. Devaluing diamond will make me seek the bare minimum to maintain it and I will take my money to Marriott or seek Hyatt status.