When "money burns a hole in someone's pocket", it means that person spends money almost as soon as he gets it -- money in, money out. So he usually does NOT have much money at any given time.
In a few months, he may have zero money or he may have a little bit (I doubt it). He doesn't know himself. So he will have to wait and see if he has any money at that future time. He can't predict it today.