"Probably, but I can't go back until I find Punu and this is the best place to look." He'll find somewhere out of the way to camp for the night and wait. It might be easier to apparate to somewhere warm and safe, but Harry has learned that he needs to make himself somewhat visible, somewhat vulnerable, for the older, more cautious shardbearers to risk approaching. They all know what he's come for, but they want to get a measure of him before relenting.