Thanks for the help everybody. I guess i was a little unclear. My cousin will already be moved into college. Picking him up before wedding (labor day weekend) wouldn't be a problem since his parents are in Houston and CLL isn't that far. They were thinking about staying in NY for a week after wedding and just putting him on a plane to IAH, but he would need to still get to CLL. The only bags he would have would be clothes for weekend in NY.

I doubt renting is an option as he is only 18. Plus he has a history with driving and my aunt is very protective. I suggested that he just take his parents car which will be parked at IAH anyways and then pick them up when they return a few days later. My aunt didn't go for it. It probably doesn't matter as the parents are having doubts about taking time away from work anyways.

I checked the link provided for the shuttle service. Unfortunately he would need it on 8/31 and there is no service that day. I'm surprised by the lack of service. I went to Cornell which is a much smaller school but still had a shuttle to SYR. Even though there was an airport with limited service in town. Combined with the fact that IAH is significantly larger than SYR makes the lack of shuttle very surprising to me. I guess everybody in Texas really does depend on cars.