I'm in the middle of a several month trip.
My older class C is towing a 3200 lb car.
I generally stay off the freeways and set the cruise at about 58 mph.
I feel comfortable with that and pull to the side if I see traffic behind me that can't pass.
I was on the freeway for one stretch because I changed the settings on the GPS and forgot to change it back to Avoid Freeways.
My next stretch of driving will be lengthier than usual. I compared the Freeway and non-freeway distance and time. 1 mile difference and 20 minutes longer.
A no brainer there. Slower and steadier without watching for the lunatics.