Flight
Houston has two main airports. Bush has many flights with all airlines, and only a little further from downtown
Flight
If you're a FF of Southwest Airlines, Hobby is your best bet and it's closer to downtown
Hotel
There any many hotels near the Galleria where the celebration is. Alternatively, you can stay in East Downtown (EaDo) near the After Party however, there are fewer hotels to choose from. In my opinion, it takes approximately 20 minutes to drive within a 5 mile radius downtown, more if it's during peak rush hour. That is, unless you're planning to visit the NASA museum which is a trek. So most areas in or near downtown should be fine.
Rental Car
Uber and Lyft are prevalent in Houston, therefore there shouldn't be a need to rent a car unless you plan to do a lot of sightseeing or just prefer to get around on your own