I've ridden it twice, south to north in '16 in 7 days and north to south last summer in 4. You can do it in 4 but you won't be spending more than a few minutes at any of the 100+ cool sites along the way. I took longer on my first time because there was so much to see; the second run was me going home from a 3 month tour and I was in a hurry. Both times were loaded solo rides. Using Google maps "supermarkets/motels near me" will show you how close all the services are to the Trace, and there are plenty, often within 1 or 2 miles. I'd spend a few extra days so your wife can have some fun too, like Elvis' birthplace in Tupelo or the recording studios in Muscle Shoals. I recommend rolling through Port Gibson and the Windsor plantation ruins just south of there. Hills aren't terribly bad on the Trace; I never dropped out of my big ring this last NtoS ride. I also enjoy big mile days and either way you'll have a good time. Returning to the Trace after a side ride into town is always a joy, as the peaceful surroundings feel like you've left society behind. I don't recommend camping at Rocky Springs Campground as it is the last part of the Trace that has not recently been remodeled and it's in rough shape. Good luck!