Plotline Conundrum

I haven't written a word today.
On purpose.

I decided I needed a short brain break.  I think I literally see smoke pouring out my ears.  My brain keeps crying like a sad puppy, just wanting a yummy bone and a nap.  So, I threw it the bone today, and let it rest.

From the actual writing that is.
It doesn't mean I haven't been thinking about it in major OCD-mode.

I have come across a plot issue I am trying to decide on.  And would love some input.  If you want to give me some...of any kind...do read on.

Ok.  So I am about 53,000 words in, give/take.  That's a good chunk.  (Typically publishers prefer a first-time author to have about 70k... or so)  I have already spent much time on different spots of the story (in prison, release, her work after release, etc), and am now nearing the climax.  The issue is, part of my pre-planned plot was that the main characters (Millie/Reed/Eddie...shall we call them MRE for this post?) were going to come across another group who was traveling towards the same destination, and join up with them.  I even have already planned the group, their back stories, all of that.  I love the characters.

But is it too much?

I am almost feeling like adding in this new group, on top of MRE, will be over kill for this story line.  I do not want it to drag on.  I want it to be amazing.  Don't all writers? (Haha)  So what do I do?  Do I still write them in, and hope that it isn't too much?  Or follow this gut feeling that now isn't the time for this group?  (Cool thought...let's say people like this novel, and I do a sequel, which I already have ideas for...I could totally bring them in then. Hm...)

What do you like when you read?  Do you like when new characters are thrown in at the end, or do you just want to keep focus on the few you have gotten to know all these pages? 

...discuss??