In Louisiana, they have the Black Rat Snake, is that what you saw? They can climb quite well, so if they can find a way to get in (no smaller than their head), yes, but no need to worry. They are large, but they are nice friendly non-venomous snakes to us humans.
Besides, very unlikely for them to try to get in, but it could be possible. Unlikely that your RV has holes in it large enough anyway, that will go to the outside to the inside.
Do you know how to email the photos from whatever you took the pictures on? What was it, a Smartphone or what?
If so, email them to me & I can post them here for you. You may send them to:
[email protected]
Have fun in New Orleans!
-Don- Auburn, CA