I still have some objections, though I do not disagree completely: First. You mention space and antarctica as examples of "new human settlements on virgin territory", and You many have a point. But:not a single person yet, as far as I know, live in space (have permanently settled there), an only a few parts in a billion people have visited space, as commonly understood(there may be some question about definitions of "space"). And I think that to a lesser degree being the case with Antarctica too.
About the future: I have a little suspicion that this century will be very different from those imediately before, exactly when it comes to "human expansion" on those fields we use to regard it as nearly self-evident. One such field is settled territory. One may ask if this may actually decline many places.
Another is population, which may decrease. The tendency has been there for some time in many areas.
I think a lot of predictions for the year 2000 have been falsified, and my impression is those tended to exaggerate human the speed of many developments.(This could be predictions of permanent human settlement on Moon, Mars or under the sea, human like robots and similar).
Then a short list of "fields" were we may have been used to expect universal expansion, but perhaps should not in the not so distant future: "territory" (including space). Population growth, which may very well be reversed.
Available resources, which in many cases might decline. Production of many kinds of goods (here I am not on familiar ground. but can nearly all groups of people continually increase their consumption and is it desirable?)
Even for tecnological development one may ask if the speed of change will perhaps slow sometime, or in some respects have done so already. (here one example:the speed of movement. In the last years, the fastest passenger plane has been buried,namely the Concorde, which had been in the air for many years - 25(?) or so).