What I'm sort of likening it to is the second season of Lost.The tail section,most of that season focused on them,they did eventually meet up with the others.In TWD,heck you could have a totally new set of survivors in just about any town out west for example,that has nothing to do with the original cast,at some point they would meet up.Anyway,an extended season is a much better idea to me,than an entirely new spinoff.
I can see that too. A second group within the main show would be ok with me even if they never met as long as it doesn't just feel like filler. They could even run across each other or items the other group left behind without actually coming together.
On an unrelated note... I just accidentally ended up on the first page of this thread when I clicked on it and some of the early posts are truly funny knowing what we know now.