I used to have Cooper ST in 285/75R16 and they were excellent for everything, except winter conditions.
They were the snot slickest tires on snow and ice that I've ever owned.
They were TERRIBLE on snow or ice, until I added extra sipes to the center treads. After that, they were pretty good.
I've had best luck on snow and ice with BFG AT and Trxus MT, but in the case of the BFG AT, that might be partly because they were narrower (33 X 10.5 R15).
I think that Cooper ST 255/85R16D with extra sipes added to center treads would be dandy for all purpose use on and off road, and be dandy on winter roads. I can't say for sure, since I never owned that size ST, but I think it's likely it'd be excellent (with extra sipes added to center treads for ice and snow).