Hun, the best way to improve your supply is to feed him more often. It might be that he is wanting a little more, or perhaps he's been drinking a bit less with all the chaos at this time of the year and your supply has dropped a bit. Either way, more frequent feeding will increase your supply, but it might take a few days.

kmn also has a good point - perhaps with all the change of routine at this time of year he just needs some extra closeness and comfort.