Well it depends on what you want.
If you have great fun in texting with her, then text with her.
If you think the timespending/sex ratio is too big, then I think you should drop it.
You could text with her now and then, not all the time, just to make sure it's still on a bit, if you know what I mean
But I wouldn't count on her coming to Amsterdam, stuff like that rarely happens.
You could reinitiate contact a bit before Manowar and then plow the shit out of her when she's in Holland. Or just drop it and plow lots of other women with the time you spend on texting her now.
It's all up to you, follow your feelings!