Being from the New Orleans area and having all my lifetime covered thousands of miles between Texas and Florida here are a few suggestions:
1::Spring starts about Jan 6,although we occasionally see colder weather in Jan and Feb it is rarely below freezing and usually only lasts a few days. Most days between Mid Jan and the end of Feb are in the 40's to 60's. Along the coast it may be even warmer.
2::Like coastal Florida, the gulf coast is a winter mecca for tourist and spring breakers but there are many places to see and stay that are not effected by this. This year Mardi Gras MG is Tuesday Feb 13. There are options for RV'ers that are reasonable even then. Private and public campgrounds in East New Orleans, Slidell, Covington and surrounding areas will give you ample options at reasonable rates and less than an hour drive to the French Quarter. Some even offer shuttle service during MG. Although the peak of the MG festivities are Feb 8 through Feb 13, in 2018, a taste can be had most weekends and even some evenings starting in Mid January; Not only in New Orleans but also in the surrounding towns such as Gretna, Metairie, Slidell and Chalmette (closer to many CG.
3::Food - The gulf coast area is known for good food of all kinds. While New Orleans has many great restaurants I personally recommend you look for the out of the way mom and pop restaurants along the way. Beware, you will likely gain 10 or more pounds on this run so plan some time for exercise or room in your wardrobe for new cloths. East Texas through Alabama are known for barbecue, Texas more for beef while the rest of the coast is more about pork products. If you eat pork you definitely want to try cochon de lait(cu-shaun-da-lay)roast pig, boudin (boo-dan)and andouille (an-do-we) sausage as well as other great pork meats in Louisiana.Personally, I always go to Best Stop near Lafayette for meat to go when passing through the area (Hwy 42 about 2 miles north of I-10). Specifically, if you are going to the New Orleans area check out [URL]www.nomenu.com a website by local food critic Tom Fitzmoris. When last I checked there was information on over 1000 restaurant in the immediate area, not counting chains!
I could write on this all day so I will end here.
3::There are lots of thing to see and do and as noted above, it would be a great idea to plan your trip to run either East to West or vis versa depending on where you originate. Perhaps begin Lake Charles or even Beaumont, Tx and drive along US 90/190. Note; at points you will be directed back towards I-10 which runs east and west. You can take side runs through Evangeline and Thibodeaux, and Cut Off, it just depends on your sense of adventure. Signs to I-10 will always bring you back to the "main road". In Mississippi run along the coast from Clairmont Harbor to Ocean Springs. Continue on through Mobile, Alabama, Orange Beach, etc and then the panhandle of Florida. If you have the time this route will take you all the way to Mexican Beach Florida before you need to head inland. As noted above there will be a few points at which you will need to leave the view of the gulf for a while but that is limited.
4::Places to stay - There are may CG both public and private along this route. Of particular note, the Silver Slipper Casino in Clairmont Harbor, MS has a gulf front camp ground and a good buffet. Island View Casino allows RV parking in their lot and has a great buffet also. The view is not as good but this one is free if you are going to the casino.
Hope this is helpful and you enjoy your trip.