I have one of those portable corrals, I've never used it. It runs off of a battery operated charger. I bought if off of a friend fairly cheap thinking it would be great. Then I read some storys about horses running through them. You really should get her used to being high lined. Will she do ok if she can put her head down to eat?
We high line ours when we camp. Thats just running a heavy rope tied high up over the horses head and tieing them to it. We usually try to park near a tree and run it from the trailer to the tree or if you can find them from tree to tree. You have to check with the camp to see if they allow this. Some places do allow picket lines to be tied to trees some don't. We use an old cinch for a "tree saver". Just wrap the cinch around the tree and then attach the rope through the buckels. Most places will allow tying to trees if you use a tree saver.
We put the horses back in the trailer at night. Vida will even occasionally lay down in there, though it scares the crap out of me.
Some friends of mine carry lightweight panels with them. They have those heavy brackets that you use to hang a gate from attched to the side of their trailer and hang them from that. The lay out of my trailer doesn't allow that (I wouldn't be able to open the side doors) so we just high line.
Here is a photo of a trip from last fall. You can see the cinch on the tree and we tie them just long enough that they can put their head down to eat hay. We just throw it on the ground.
Some campgrounds have equestrian camping areas. Those are great when you can find them. They usually have some sort of horse containment already set up. Anything from pipe pens to posts for high lining to to just hitching rails at each campsite.
Take a muck bucket or something to put poo in and a fork with you. most places require that you clean the poop out of the campsite before you leave. They usually just want it moved someplace else you don't have to take it home with you