Before being called out on it: I realize that this is a specific question, however I think the theme is something there is very little information about. I already have posted about this on some pickup forum, but got turned off by the responses and rate of sad, misogynist stuff I found on the site. Figure there will be better responses here.

The problem, skipping too specific things: I met a girl on tinder I am interested in. She also seemed interested, but when we tried setting up a date, we found out nothing fit before I'm going home and I'm coming back after new year, in over a month. So I asked for her number saying we could talk then, and got it. Now I have the number, but I don't believe waiting for a month and then texting/calling her is a good idea. What should I do?

The reason I think fits as a more general question is that basically all advice on "texting/phone game" is about using it to set up a date. What I need to know here is, how do you use it to keep a girl you barely know interested? After all, the normal thing is to make plans together and go from there. Our plans are to "talk after newyear", and all we had before that was a tinder conversation. I don't see that holding.