Wind resistance, more than weight, is the primary factor when considering how well your drive train can tow. Imagine towing a flatbed trailer with a sheet of plywood lengthways... it will tow easily, right? But turn that plywood sideways against the wind, and that will be much harder to tow. Has the weight changed? No. Only the wind resistance changed.
So you might be able to successfully tow a trailer with a small frontal area. Ford's 30 square foot recommendation is an indicator that your performance will decline, the drive train will struggle and strain, with big, boxy trailers.
A popup trailer is a good candidate. In non-popup travel trailers, your best bet would be a 13' or 16' Scamp, Casita, Lil Snoozy, Eggcamper, or similar trailer. These have smooth, rounded edges and narrow, low bodies that will minimize wind drag. If you chose such a trailer, you should plan to keep it at 60 mph or lower on the flat highways, with overdrive locked out. On hills, slow down more and downshift when necessary (your Escape, like most gas engine vehicles, generates considerably more power at higher engine RPM). Anything larger could be problematic, unless you want to slow down even more.
Take a look at my signature for my rig. My Highlander has 270 HP and is rated to tow 5000 lbs. My TT is about 2700 lbs loaded, and only 7' wide by 8.25' high. The HL does tow that TT all right, but in the mountains this summer I was wishing for more oomph. My next tug will have a more powerful engine!
You live in MN, so why not tour the Scamp factory in Backus? See for yourself if they make a floor plan you can live with.
The other problem you face with the Vibe (and this is a big problem) is its dry hitch weight of 310 lbs. By the time you fill your propane tanks and fresh water tank and add just a few basic items to your trailer, I can almost guarantee you the hitch will be 450 lbs or more. Your Escape cannot handle that. If you don't tear the receiver off the Escape's back end from that weight, at the least your rear suspension will be destroyed in no time and handling (with your front end in the air) will be horrible. The only way I would ever tow that Vibe with the Escape would be if I spent a couple grand on a custom-fabricated hitch receiver and a weight distribution hitch, plus maybe different size tires and a sway bar for improved handling and some aftermarket suspension components and a tranny cooler (get the picture?). I think Road Ruler would agree that the best place we know of for such a setup is Can-Am RV in Ontario.
Now, I understand you liking your Escape and owing $14K on it. You bought the Escape used, right? So, how much is it worth now? You probably could sell it outright for what you owe on it, and start over with something more capable. For the Vibe, look for something with at least 6000 lbs tow/ 600 hitch wt capacity and (at least a bit) longer wheelbase than the Escape.
I hope that helps you.
