800 lbs isn't that much. Your batteries aren't included in the dry weight. If you plan on boondocking you should get two, 6V golf cart batteries are best. That would add over 120 lbs. Dry weight doesn't include the water in the water heater, 50 lbs. If you fill your fresh water tank because you don't have water where you;re camping that's 250 lbs. You probably will want a better mattress, that will add 30 lbs or so. And we haven't even gotten to food, beverages, and clothing etc....
A Colorado with a tow package would be fine, but if you like SUV's (it sounds like you do) there are plenty of choices there too.
Here's what my dad always warned me about salespeople: Are they in sales? Is their mouth moving? Then they are lying. It's always served me well. You can't really blame them, that's their livelihood...
Sounds like you bought the trailer you wanted and were already planning to upgrade your TV, And you've come to the right place for unbiased advice. So, you're doing good!