Girl agreeing to go out with you is a very good sign, it is a good start and try to move things fast before the time limit.

I did just that few years ago, got her to bed after about 1 or 2 months after things worked out very well. Then she went for her postgraduate study. Once she is there, things took a turn for the worse. She is gradually getting less and less involved in maintaining the connection, people said LDR has a very high failure rate, it is true, it is not even your fault sometimes, you are doing your best to maintain it but the other party is not doing their part.

When she got back from oversea, the vibe isn't there anymore for us to continue.
The real sweet times are before she leave, I enjoyed every last bit of that, anything after that is just pure nightmare.

I would say, just go ahead, do what you want, and have fun.
She will be oversea anyway, if things end up well, then you had your fun, if it doesn't she will not in MY after that, you won't see her again, nothing to lose.