I've potty trained dozens of children. It's completely normal for her to run hot and cold about using the potty right now. You are absolutely right not to push her.
As for going out of town - I think it will be easier on you just to use pull ups. Potty training and traveling do not go well together! So if you're training her on the road, consider whether you want to be dealing with the public restrooms.
Personally, I think public restrooms are icky. I always held my children up in a sitting position over the toilet so they didn't touch anything. One arm behind their back, one under their knees. Trying to back away as much as possible so nothing splashed on my clothes! Then trying to get the toilet paper for them! OMgosh, it makes me laugh remembering that!
I never gave treats to my children for using the potty. (But then I never trained really trained them, they trained themselves) I just told them how proud I was. But the other children I've trained, (because their parents did give them treats) I would just give one - yes, ONE - M&M to them, each time they used the potty. And it would only be if they used it, not when they just sat on it. Some parents would give them a treat every time they even sat on the darn thing, so they'd say they had to go every 2 minutes!
Good luck!