On the quest Ed-e my love whitney cleary says one of our outposts in Chicago so wouldn't that mean they have about the same amount of people as the Mojove bos probably more?

Thats my theory. I'd say, based on what I would guess is the amount that likely survived after Broken Steel, combined with the amount that was probably there orginally, the Enclave garrison at Chicago is about equal to or a bit greater than the Mojave BOS in size. They probably have a few vertibirds too that managed to get out of AAFB.

That's what I've always thought really hope you can join them in the next game

And I really hope if you can join them there is a proper ending where they kill you after you've out lived your usefulness as your not part of the pure humanity.

I hope that it's only a small outpost of 20 guys

What if your from a vault?