Can I multigroup with just one camera?
No, unfortunately you can’t. The premise of multigrouping is to take the footage of multiple cameras and link them together so that they can be viewed simultaneously.
Your best bet would be to string all the clips out into a sequence because all of the clips would be in the same location (like a multigroup) and you wouldn’t have to click on multiple clips to view all of the footage. Be careful when using it because if you double click on this “clip sequence” it will load in the timeline window and you will lose all of your undos. (I hate it when that happens to me!)