I absolutely love towing my 31 ft. 7000# GVWR trailer with my 2015 Canyon V6 with TowHaul!!!! I've had it for two years now and put on 12,000+ mi. towing. Our first major trip was a three month tour of New England states and this last summer we spent 2 months in the northern Rocky's (Glacer, Black Hills, Banff, Jasper). We're planning another two month trip to the southeast coast for this coming spring. (We're retired).
As you already know, the Canyon is narrower than a full sized pickup which makes it MUCH EASIER to park in crowded sightseeing/tourist trap parking lots and gets over 20+ mpg when not towing. Flat road towing with a good tailwind will get you 11-12+ MPG towing. However, a 30 MPH headwind will drop you down to about 5 MPG (I successfully out ran a bad cold front with hail from Fargo to Minneapolis, but I didn't pass up too many gas stations).
Your Canyon will handle any TT up to 7K# (GVWR). A 7K TT will require a good WDH that is correctly setup to avoid overloading the hitch and to reduce sway. For a TT recommendation: If you prefer a quick getup and go camping, look at TT in the 25-27 ft range with no slideouts because they're easier to maintain and easier to get a site at a crowded SP. If you prefer to setup a trailer for a week or two with FHU and explore the neighborhood, then look at a 28-32 TT with slideouts (you won't be falling over each other on rainy days).
If you want more info on my setup, send me a PM, I'll be happy to share my info with you.