It will be much easier now with Gedocm 2.0 as you can process at your leisure, new people do not get added automatically. For example I have just uploaded a gedcom file of 1166 people I knew to be descendents (or husband/wifes of descendents) of a single person. May of these people I had already previously to wikitree a year before but I did not know which ones I had not yet added.
So over a period of a couple of weeks I have been checking matches, updating existing profiles with new information (mainly fixing firstname/middle name bug in Gedcom version 1 and adding more accurate birth dates and death dates)
I was then left with about 150 people that were not yet in Wikitree that I added in using Gecompare.
The whole process was a bit of an effort but worked quite well, once various bugs are fixed it should be quicker to do such an import.