I had a session at the Northbrook location a few years ago.  I remember that we drove in separately, and that I checked in before her arrival. We were not at the desk at the same time.  
I’m not sure if there is a bar/restaurant nearby.  
You could always meet her uber at the front and walk together.

I was there

Recently on a Sunday...girl parked at a small strip mall a couple of blocked south
Most if not all of the stores were closed
We did an afternoon nap...overnights might be tricky...might want to find a 24 hour business for that IMO

Just give her the gate code

PARKING

There is only one parking space at each cabin

I've had a few meetings at the Sybaris, all went well.  I was given the gate key when visiting the one with gate keys (not all Sybarises have them like the one in Northbrook does)  I've never had a problem parking, just parked right there.  Some of them have garages, others don't.  Personally, parking a few blocks away and walking over makes me nervous and looks suspicious on camera, particularly at a place set up for couples.  

Every meeting I've had there was amazing, I really enjoyed the atmosphere and the gentleman that was so thoughtful and generous enough to set up such a wonderful experience.  It doesn't matter if it's just a little hot tub suite or  the suite with the pool, sauna, hot tub and all the bells and whistles.  A good time is up to me and my partner, not our surroundings.  

I think you'll really enjoy your time with her there