They say a BPD won't run off for real unless they have someone waiting in the wings. I guess if I were you I would be prepared to hear sometime soon that she is seeing someone else.
That being said, yes, I do believe she will be back. Probably within the next month. But it is anyone's guess.
Many of us have experienced the dumping and exiting, only for them to come back. Or for them to get really mad or overwhelmed and give silent treatment over and over until the non learns better communication skills or simply doesn't react to the antics. So I am told

My boyfriend has decided to pretty much be absent and give me the silent treatment until he has "rested". He has done this sort of thing 2-3 times in the last year and prior to that while he was cheating about 6-7 times, was gone for about 6 weeks in one year. Before that it was 1-2 day events every few months.
It really can wear on a person.
I think you're probably right. I do get the impression that she might have found someone else nearby hence the emphasis that the long distance nature of our relationship is unsatisfying for her. I doubt she will explicitly tell me she's seeing someone else, she's rarely directly hurtful towards me like that, but the last few times we talked, the day after she texted me to wish me Merry Christmas, she insisted that she "had to leave" and "was going out with friends."
I don't know much about her relationships with other people, but unless she's found an exceptional person I don't expect it would last very long. Once a certain level of intimacy is established it's not long until she decides she can never see a person again.