I have not been to Jellystone in Gatlinburg. The 2 previous Jellystones I have stayed in, your rig would have been tight. Both that I stayed in, my 26 foot travel trailer would have been tight and the sites were not level. I am sure this is not the same as all Jellystones. I know my kids liked both because of the abundance of activities offered.
i have not stayed at jellystone but i have drove though the one on hwy 321 and yes it would be a tight fit but it can be done interior roads are close and trees every were becarefull would unhook tow car before i enter the park at the office i would stay at smokey bear just 5 mins up the road from jelleystone but thats just me good luck
I've been there a few times. The last time there was a 45' Prevost towing a Hummer. So yes, your 37 footer would fit - but don't expect to get a site that large without a reservation.
Jellystone does have some sites that are large enough. The owners are really great. Give them a call and explain what you are looking for. Last time we were there, we were in site #31. Site #32 was empty (it is the last site that they fill)... and in #33 was a brand new Prevost with a ? don't remember what they were towing.