@wolfkeller - Did you ever come to a solution?
From someone in nearly the same situation as you (national touring tribute), I went with my own personal wireless IEM system for the last two tours and it's been a godsend. Most of our tours are fly-in, play a long weekend or week-long run, and fly out. Backline is either provided, rented, or coopted from local opening acts. We travel in minivans - so the idea of a full band IEM rack setup is a non-starter. But, I realized that the left side of the stage monitor mix was completely different from mine, and our drummer uses IEM's (and no wedge other than kick and a little vocal), so I had to make the switch to IEM so I could hear myself anywhere on stage....or backstage...or in the parking lot.
I rely on the in-house monitor mix guy or FOH guy - most of whom are so used to IEM's now they have no problem with me. I put my transmitter right on their mixing desk and they plug an XLR from an aux send for me. During soundcheck I do the same thing I always have done - point a finger in the air when he going through each of the drums/guitar/vocals until the volume of each is where I want it. Then fine-tune after playing a song or two during soundcheck.
I absolutely went over-kill with my custom IEM's and splurged on 64Audio A8's - which are just the best headphones for anything I've ever used. I now use them pretty much daily for everything from music to movies. They are also very good earplugs for flying or catching a nap.
For my wireless, I went against the norm and opted for a Mipro MI909 unit. It's completely digital and just isn't that well-known in the US. It's been a rockstar for me - was cheaper than (what I felt were) lesser Sennheiser or Shure units, and makes me feel like my money was spent on a quality unit - not copious advertising and marketing. I got it from here:
MI-909TR Digital Stereo Wireless In Ear Monitor System at In Ear Gear.com (not knocking Senn or Shure at all - my bass wireless is a Shure GLX and it's amazing)
My drummer is wired and uses Ultimate Ears with an Ultimate Ears SoundTap box. But we're the only two in the band currently with IEM.
My fly-rig is a bass in a gig bag, and a double-wide laptop bag that carries my pedalboard and wireless IEM rig. That's it.
ps - one added benefit is that my guitarist can now mirror his mix into the wedge normally in front of me and he can roam the stage freely.