You should keep the liquid ant bait under all the sinks and the couch in the RV at all times. That will 'prevent' you from being over run by the pesky southern ants.
Every time you park sprinkle "powered" Sevin (can be found at Tractor Supply stores)all around the tires of your RV and everything that touches the ground. Make sure you sprinkle it on and over all cords and water hoses coming from your RV.
And 'never leave anything propped up against the side of your MH.
Being proactive like you requested IS the best way to keep these ants out of an RV. If allowed to come in and flourish it takes 'weeks' to get rid of them.
Being a newbie first time in Florida I didn't know all of this and was over run by ants in the MH. :(
After buying just about every ant bait this is the only one that really worked. "Liquid' ant bait. Make sure to keep away from your pets.
If you do all of the above you should be free of ants. So head on down south the weather is fine! :C