I am not known to be a negative person in general but I would like to mention some shortcomings with trailers for bicycles since I have pulled lots of them for various reasons.

First - good things about trailers!
1. Like you, hooking up racks to certain bikes is difficult (but almost never impossible).
2. For large riders, getting the weight of gear onto three or four wheels helps prevent breaking the bike.
3. For back-country tours with tons of river crossings/portages, like the Continental Divide route, it is much easier to drop the trailer, carry the bike across, then carry the trailer across, than to jettison four panniers every time, the reattach again and again and again.
4. When you get to camp, drop the trailer in two seconds and use your ATB as it was meant to be used for fun - no luggage or racks. Ride some trails, explore some rutted dirt roads, etc.
5. With a trailer, one bike does it all.
6. Obviously, you can carry bigger stuff, like art canvas and paint kit, easel and a lawn chair ( I met a fellow doing just that on the PCH ).
7. Some trailers are actually lighter than racks and paniers combined.

OK...now the bad news as I have discovered over time.
1. You cannot bunny-hop a trailer. I was flying down HWY 1 in Cali at 50 mph with traffic inches away on my left, sheer drop to death on my right. I rounded a curve and there was a two foot chunk of tarmac MISSING from the edge of the road. On my loaded touring bike I managed to unweight the bike with a small bunny-hop to sail over the hole easily. Had I been hauling a trailer I would be dead. This is extreme, but there will be all sorts of less deadly road hazards that you can easily hop over on two wheels but your trailer will SLAM into them every time. Just riding up a curb can be a menace.
2. Due to lower tire pressures on most trailers, they use more of your pedaling energy. So your days may have to be shorter too.
3. Another tube size to carry with you. More tires to go flat.
4. Two-wheeled trailers will always have their right wheel in the dirt/glass/thorns at the edge of the road. See #3.
5. Two-wheeled trailers make you ride further into traffic.
6. Two-wheeled trailers and highway rumble strips make you ride completely in the travel lane.

Suggestions:
Travel light, don't cook, don't camp, bring a credit card and a change of clothes.
If you camp, goosedown bags, self-inflating pads, and 1-person tents are TINY and light.
Use a rack that attaches to your seat post. Most will carry 20 lbs. Make sure you have a good seat post! Maybe a handlebar bag too. Racks exist for double-sprung ATBs with disk brakes. Try Old Man Mountain.
A small "Camelbak" style backpack with a thin hip belt is not too bad during mild weather. The hip belt supports the weight, not your shoulders. A large fanny-pack with a proper hip belt (Mountainsmith) can carry as much as a small backpack. Again, weight on your hips seem to just disappear.
Get a trailer for your dog. Leave it at home for your short tour.
And the obvious: Get a bike suited for racks and panniers. No law against owning several bikes.

I hope this helps...

Cheers!