It's payload rating/tongue weight rating, not tow rating, that limits these light trucks in actual tow capacity.
Looking at the GM brochures, dependent on trim level/options, it appears either the 2015 (message title) or 2013 (message content) Tahoe will have a real world payload rating of around 1400-1500 lbs. Subtract the X213 appx 750lb tongue weight and a 100 lb. WD hitch, and you have only about 550-650lbs left for people and gear.
An Envoy has even less payload capacity let's all be careful out there
1500HD or better recommended.