Just some advice, take it or leave it that's up to you, but think of the worst case scenario & ask your self if it's worth the trouble. Best case, from what I have read over the past year, most ships here are getting self-disembark going between 7:30-8:30am. If that happens you are probably leaving the port around 30 minutes after walking off the ship with a 90 minute drive to the air port (IAH) with no traffic. In that case yes it is doable.
But worst case, there is fog in the port that morning and the ship doesn't dock till after 8 or 9am (I have been watching the web cams the past month for our upcoming May cruise and most are docked by 6:30am but no fog this time of year). That could mean self-disembark starts at 9 or 10am or later. That puts you at the airport (again with no traffic or road construction) right around 11am or 12pm. What if your shuttle is running late or you use Uber/Lyft & they keep dropping your fare (I have seen reports of this happening)? I will also take this time to say that I45 south has been under construction for the past 10 years, with varying lane closures once or twice a month on the weekends, and it is still not done (I drive south bound a couple time a month on I45 during the morning on the weekends and had to deal with it several times). It is a real gamble to try any flights from IAH before 2pm in my opinion. You can make it if everything goes right, but it only takes 1 thing to go wrong and your missing you flight. I wish you best of luck with your travels no matter which you chose.