We left from my mom's house on the NW side of Houston at about 7:30 - 8 AM - took the Sam Houston Parkway north loop around to I-10. We got to Tallahassee late that evening - about 8 or 9 Eastern Time. There are a bunch of hotels at the Tallahassee exits. They recently renumbered all the Florida exits on the interstates, so make sure you have to correct one for your hotel. There are LaQuintas, Comfort Inns, a few more at one or other exit at Tallahassee. We stayed at a Comfort Suite over by the University since we wanted the queen sized beds instead of doubles. If you think you will be staying at hotels a few times a year, sign up for their "frequent flyer" cards. When you stay about 10 nights, you get a free night. We have the card for Choice Hotels (Comfort, Quality, etc), Hilton Honors (Hilton, Hampton, etc) and Holiday Inn. When you make your reservation, give your card number.
When you leave Tallahassee in the AM, you will only be about 4 hours away.
If you only want to drive halfway, stop in Daphne AL, on the east side of Mobile Bay. There is a Comfort Suites and Hampton Inn at that exit. Both are very nice and new. We have stayed at both several times. You have about 8 hours to go from there. Pensacola is about an hour away from Daphne.
If you stay at Pensacola, there aren't as many right on the interstate if I recall correctly. After Pensacola, you won't find much until Tallahassee.
Make sure you take I-12 in Baton Rouge and don't go to NO. You will add at least an hour to your trip if you do. You pick up I-10 again at Slidell, just before you get to MS.