We may lose the sea ice and continental glaciers, but we'll probably still retain some ice with the intersection of extreme altitudes and extreme latitudes, at least for our lifetimes. A place like Denali is a lifeboat.
I think this is more accurate than you may have intended. It will be a single lifeboat, when the Titanic is sinking. Quite useful if you can get on it, and would guarantee survival, but for an awful small number relative to how many would like to be onboard.
The supposed Biblical Ark only held 2-7 of each animal. Denali is a big mountain, and will make a rather large zoo or a small nature preserve. But there are other Arctic ranges with less extreme altitudes that are going to prove useful as well in the "extremely alarmist and not worth considering seriously" scenarios that some of the data suggests we're heading towards.
There is a question of whether there will be any space, what with all the condos. But humans are less constrained, having invented the pressurized condensation-evaporation heat pump refrigeration cycle, than the natural world.
