That is probably the fastest route, but never towed anything larger than a large popup, with a '15 Silverado and had no problems. Hwy 50 is AKA a Interstate 70. Takes you through the middle of the San Rafael swell with some great places to pull off on 70 and view.
However, if you have the time, another route, longer but more picturesque is:
Hwy 12 to Torrey, east on 24 (through Capital Reef National Park), then north on 95 at Hanksville up to I70, then east to Hwy 191, south to Canyonlands. Not much further, but Capital Reef is an amazing park and has some great hikes.
However, there is are some steep grades (8-14) on Hwy 12, I believe the 8 percent is long, but the 14 is not (this is from memory, last time I traveled it was about 4 years ago; narrow in some areas south of Boulder to Escalante but again, absolutely no problem pulling a large popup, about 3200 lbs, with a '13 Silverado.
Trailer: Lifted 228BH, heavy duty springs and Yokohama tires DELAMINATED ROOF
TV: 2016 GMC Sierra Z71 4x4 CC, SLT
Spare TV: Two Alaskan Malamutes
Living somewhere in ID; previously lived in Moab UT; previous to that, don't ask!