I looked at the GMC online brochure again and this is what it lists for the following dimensions for the Crew Cab long-bed V-6 4WD:
GVWR = 6000 lbs.
Body width = 74.3 in.
Overall length = 225.0 in.
Inside width between the wheel housing = 44.4 in.
Box length at floor = 74.0
The brochure does not show the curb weight anywhere that I can find so I checked various other sources that popped up from a Google search. The curb weights given varied from 4266 lbs. to 4500 lbs. I have no explanation for the differences.
NOTE: These figures were taken from sources for the GMC Canyon. I assume that the Chevy version will have the same or very similar numbers.
For those of you who might be setting up your Canyon for flat towing behind a motorhome, I did find a chart that said that the 4WD automatic-transmission version is flat towable following the procedures in the owner's manual to shift the transfer case into neutral. The 2WD version is not approved for flat towing. In order to flat tow, there is a requirement that you disconnect the negative cable of the battery. Doesn't say why.
Hope this info is helpful ...