Look, if you leave early enough in the morning like before 8am then heading straight up through Sevierville should not be an issue traffic wise really although that would not be my preferred route. If you want to take 321 then you should because it isn't that intimidating at all. That would be the way I would go. It cuts off a few miles and it takes you around Maryville. Just stay on 321 and it connects to 40. If you go up the parkway to pick up 40 then you have to go through Knoxville on 40 and it can be awful traffic wise. Taking 321 bypasses K'ville. I have a 37 foot travel trailer and I would tow my rig on it without hesitation. Been on it many times.....I live in Dandridge and have been through that area many times. Hope you enjoyed your stay here in the land of Dolly.