I've towed a 3200ish (loaded) pop up trailer quite a bit with a 2010 Honda Pilot and it handles it great, so it is possible that a solid modern unibody vehicle can tow small loads fairly well. I generally get 16-17 mpg to boot.
Now the caveats. A Pilot isn't a Highlander, obviously, and it has quite a bit higher tow rating (4500 lbs). It also isn't a hybrid (I don't really know how that would play into things). Lastly, a pop up is a much different animal than full height TT which is going to push a lot more wind.
My sense is that you'd be pushing it a bit with that trailer and TV combo.