I'm a few thousand miles from my tent so I can't confirm the width for you. I can detail my experiences with this RTT. Overall, I love it. I won't go into ground vs RTT since you seem to have made that decision already.
-The mattress isn't supportive enough for me. I'm 6'2" 215 lbs (you can convert that to Canuck on your own) and a side sleeper. I added a cheap queen size pillow top and it's great now.
-The mattress won't stay attached to the tent floor if you have sheets or the above pillow top on it. There is Velcro on the bottom corners of the mattress to hold it which is covered by the sheets. Not too serious but a concern you need to watch out for when deploying the tent.
-I have some small tears in the window netting from the side windows dragging against the hinges when folding. Be careful to keep the windows from the hinges. Rookie mistake that just takes a bit of mesh repair. No little flying bugs in the SoCal desert to worry me anyway.
-One of the straps that holds the crossbars together on the inside ripped the loop where it was attached to the crossbar. Easy sew job to fix, but looked like a poor stitch job from the factory.
-Bolts on one hinge came loose, we're not tight from the factory. Locktite and some wrench work fixed it easy. Should have done this when I got the tent.
-I wanted to get an extra set of mounting hardware so I called ARB USA. Had a long conversation with the service rep who gave some tips for using the tent and care. Customer service is A+ in my book. They also helped me trouble shoot my ARB fridge issue at OVX a few years ago. Turned out to be my wiring, but they took time to help me trace it out and fix it.
Overall I'm very happy with mine. If I think of anything else I can add to this...