I am helping my daughter map out a trip she will take with two friends when they graduate from college in May to bring her vehicle back from the NYC area to California. The western portion has been figured out from Oklahoma City to points west as she did a similiar trip last summer. To mix it up somewhat she'd like to see Nashville and Memphis. Google Maps offers the I-81 route including through Knoxville and the I-68/I-64 through Lexington. The latter is our current leaning but was wondering if this route is very mountainous/cold for May? Forgive my ignorance - I'm just basing this on the satellite imagery on google maps. I'm sure both routes have their pros and would love for anyone to weigh in on the matter. They would be driving this mid-week not on a weekend. Thanks - and they will not be driving straight through. will Make at least one stop before Nashville.