This is one of the most frequently asked questions....."3500#........?" 3500# sounds like a great number until you find that it's darned near impossible to actually stay BELOW that number. You'll hear dry weight, GVWR, CCC and all sorts of things that add into the equation. The bottom line is that the 3500# is AFTER things may be added like the awning, the battery, full propane tanks, food, clothes, "stuff", dishes and cookware and so on. Somewhere in here comes a weight distribution hitch and whether or not your Honda is rated for one. And that frontal area. Towing a 3500# boat or flat-bed type trailer is totally different than the 3500# travel trailer because as has been said, it's like pulling a barn door down the road. Then there is the 1000# or a percentage that I never can remember that you need to allow for.
Strongly suggest you get the exact specs from your dealer by taking your VIN# and making sure what you think you have is really correct. Don't trust the owners manual. Then start looking online at the Rockwood ROO, the various Jaycos and other models. You don't want 3500# to be the final number, you've still got to allow for all these other things. Rule #1 in shopping for a travel trailer is to take what the salesman tells you with a grain of salt....some don't have a clue and some stretch the truth. Do your own homework.
Agree that the 17' is about max - and maybe more than max - for your Honda. If you don't necessarily need both bunks, KZ Sportsmen makes a couple of models with only 1 bunk, and IIRC one is 13' and the other around 15'. I've seen the 13' and it's not a bad little hybrid at all....more than you'd expect in that size trailer. For sure, you'd be good with the weight.
Minivans are great vehicles, just not for towing a trailer. Your #1 priority has to be safety, the other stuff comes in a distant 2nd. So my suggestion would be to start getting all your numbers together, know to begin with that you won't get everything you might want in the size trailer you can safely tow and triple check everything before you sign on the dotted line. It can be done, but you've got some work to do first.