Looks like we have a similar setup with TV and pop up. Cool.
I am not sure of your 18 Gal tote dimensions but one of the things I was toying with was mounting the blue tote under the camper. I have seen a few mods like this where people make aluminum racks underneath.
I found that just behind the stairs you will find space to mount the blue tote. I used two bungee cords in an X pattern to hold it up. It actually fit pretty well. You will find that the frame has holes in it to run the various cables through. These holes are ideal for using as bungee cord attachment points. The blue tote should be pushed right up to the frame rails and the 3" access port will fit nicely up against the wooded floor in the gap.
It is worth a try. I only bring the tote if I am camping with W/E. I leave it if I book a W/E/S site. So depending on how many times a year you go without a sewer, you may find that the easiest no fuss way is to just tie it up under the pop up like I explained above.
P.S. Do you have the tow package in your Tahoe? I do not. I have an LT model with 3.08 gears to tow 5,200lbs. I do not have an external transmission oil cooler. I am going to install one soon as I think we are pushing close to the limits with this pop up and all the stuff we carry for camping in the TV.
Watch the e-trailer install video on the 2011 suburban. It looks very doable. Hardest thing will be getting the front grill assembly off.