>Despite the harsh conditions on the surface, the atmospheric pressure and temperature at about 50 km to 65 km above the surface of the planet is nearly the same as that of the Earth, making its upper atmosphere the most Earth-like area in the Solar System, even more so than the surface of Mars. Due to the similarity in pressure and temperature and the fact that breathable air (21% oxygen, 78% nitrogen) is a lifting gas on Venus in the same way that helium is a lifting gas on Earth, the upper atmosphere has been proposed as a location for both exploration and colonization.
On the surface at least. If there are indeed frozen over oceans on the moons of the outer planets this could be one of the best places for habitation eventually. It won't be very familiar to us but we know how to build things that can survive under water at intense pressures. A thick layer of ice helps with the radiation and in the case of a liquid water oceans we know it will be a fairly comfortable place to live. With the right technology we could probably live underground on many moons and planets. The tricky part would be making them self-sustainable which isn't even a deal breaker if you can direct an icy asteroid to the right spot on the surface and do something useful with it afterwards. As a species we're even preparing ourselves for living under the surface. Many of us sit inside buildings the vast majority of our lives. Psychologically I think it wouldn't be a huge leap. The biggest problem we can't even speculate much about solving is gravity. Even if it's not too extreme the effects are pretty rough on the body.
I've thought about this, your example and also moon or mars bases. While theoretically possible, the thought of trying to do major underground construction (with limited resources) in a space suit seems wildly impractical.
