i agree removing it is the worst idea, and making it require lvl 100 is also bad, cause end game for a casual hardcore player is more like lvl 80, really it should just require you be in world tier 4 to use cheat death, i would be somewhat fine with that but really i wish it would just stay in the game at the same resource cost, maybe make the cooldown higher, but i think you can remove the cooldown by just logging out.
the best bet is just give us a passive buff after staying online for one hour we get a cheat death with a 15 minute cooldown and comes back after an hour of it procing or being logged back in again, remove the scrolls of escape as a usable item and just do what poe does and log us out safely when we dc.
so far the devs have not talked about changes to s4 yet, and hopefully they go back and decide to keep the potions rather then hurt the majority of the hardcore community. without cheat death potion i wont be running wt4 world bosses unless theirs some players who one shot it cause the world bosses are the current main unplayable part of the game i lag the most.
EDIT-remove all one shots in the game before removing cheat death potions, decrease enemy damage or give us more toughness on gear and even more so on the uniques.