...and assuming that "we" is again yourself and your girlfriend, then you might want to aim for a relaxed mix of some forested mountain retreats, vibrant nightlife, and Deep South river experiences. From Charlotte start out headed west for Great Smoky Mountains National Park. As with all National Parks, they have hikes of all lengths and strenuousness, so I'm sure they'll have something to suit your desired activity level. The same is generally true of National Forests, such as Nantahala, but they are generally much less developed than National Parks and Ranger Stations may be much more difficult to find for information. Another national resource are the National Recreation Areas (NRAs) such as the Big South Fork National River and Recreation Area which would also be on your way, more or less, across Tennessee.
In Nashville, you'll want to check out both the current Grand Ole Opry and its former traditional home at the Ryman Auditorium. Then in Memphis, plan on spending at least one evening strolling along Beale Street and taking an auditory sampling of the many clubs. Another spot you may want to visit is the old Sun Studios where Elvis, Johnny Cash, Carl Perkins, Jerry Lee Lewis and others got their starts.
Of course, you should take advantage of the freedom of the road and take a completely different route back to Charlotte. US-78 east out of Memphis will take you to Tupelo, MS and another Elvis shrine. Then a place that might surprise you, the U.S. Space & Rocket Center on Huntsville, AL. From there, you can follow the Cherokee Foothills Scenic Highway across northwestern South Carolina and back into the Charlotte area.
AZBuck