Plot hole: The sheer distances Kevin covers on foot in one night are outrageous. Between 9pm and midnight he walks from Carnegie Hall to the children's hospital, to 95th street, back to the toy store carrying a large paint can and a large 2x4 (street signs here put it around 59th and 5th), back up to 95th, then all the way back to midtown, to Rockefeller Plaza. One way from W 95th street to around E 59th and 5th Ave. is at least an hour on foot for an adult, he does this 4 times between 9pm and midnight, once while carrying a 2x4 and paint can, once while being chased by 2 adults, and he still has time to set up a house full of traps.
Plot hole: There is absolutely no way that a hotel staff employee would ever let a child check in alone. The staff would be required to personally contact the owner of the credit card Kevin hands them personally to make a reservation, not to mention Kevin never had his dad's government I.D on hand, so there was no proof of verification whatsoever, which is also required. Not possible today or even back then, especially considering the lawsuits, terminations, and bad press that it could lead too.
Answer: He's heading back to the hotel most likely to apologize for spending such a huge amount.