What is too long to get into State/National Parks?

We have a FL 40' fiver and have zero issue fitting into state and COE campgrounds in Alabama and Georgia. Some are tight. Remember the back of your fiver can hang off the back of the pad as long as you can put down your rear stabilizers. Our new unit will have six point leveling which will allow us to back in even further. Use Google maps to look at sights and roads. I've had more issues with low branches than length. Good luck and happy camping.