I'm sorry I didn't fully understand your problem from the original post, I was just adding the link to the post about hardwiring a 2nd AC.
I had a similar problem at my tailgate site, last year they added power pedestals, but they were only 30A. I had an end spot which gave me access to both sides of the 30A pedestal. I bought a 30A/30A to 50A Y adapter which delivered 30As to both sides of the panel allowing me to run two ACs.
If you have access to an additional 20A plug you could use a similar 15A/30A to 50A Y adapter to the same affect.
When hooked up this way I'll usually run the fridge & water heater on propane to take some of the load off the panel. If you have 45A to the panel running two ACs will not leave room for much else and you'll need every bit of it to start the ACs.
Amazon.com: Camco 55025 PowerGrip Maximizer 45 AMP Adapter: Automotive