TNO = trans neptunian object, basically far out dwarf planet
Obviously there would be less sun to greenhouse, but theoretically could that be a way to have closer-to-earth habitats far away from a star?
edit: the TNO does not have to be like Pluto, it can be bigger or have different conditions
Well, if you want an atmosphere to start with, might try running numbers for sulfur hexafluoride. I don’t know if it’d be your best option, but I’d guess that it’d be up there if you can keep the object warm enough for it to be a gas.
https://www.epa.gov/eps-partnership/sulfur-hexafluoride-sf6-basics
I don’t know how to calculate albedo, but I’m sure that there are Web pages out there talking about it.
EDIT: If all you care about is keeping the body warm via solar radiation and you don’t care about it specifically using purely the greenhouse effect, you could use space mirrors in orbit.