I’ve heard an interesting proposal in this regard by Richard P. Speck of Micro-Space Inc. Now it does seem a little crazy, but he proposes sending a “camping” expedition to Mars, where the day-to-day operations would be carried out in a portable inflatable tent, now supplies would have to be landed, and I think he proposes a single site “depot” that you would enter, pick up your box of supplies, and go out to the tent. I propose a “dog sled” type mission along the same vain. Although I don’t know how you would reconcile that with being able to anytime abort to orbit...
The success of the little rovers suggests to me (it’s around here on FR somewhere) that a big winnebago kind of thing would make an excellent station. It could be sent crewless, landed, and checked out remotely from Earth, and then double-checked by the crew arriving in Mars orbit sometime thereafter. The third component (also sent crewless) would be the de-/re-orbit vehicle. The second component (the one with the crew) would have everything needed to go, enter orbit, leave orbit, and return to Earth (to maximize safety).
The surface habitat would be mobile, to maximize convenience, and as you said, to provide a shirtsleeve environment. It would be photovoltaic powered, with some kind of fuel cell backup. The big bubbles and the like could arrive later (and whenever, and wherever) and self-deploy, or the crew could do the needed work during EVA.
The winnebago (the “Ares-stream” might be more appropriate) would last for years, and crews could come and go. It would be left on the surface, and the access to and from the surface would be via that third component. I wonder about reuseability of the de-/re-orbit vehicle (perhaps it could be built to require only refueling).
:’)