I would recommend calling the camp office and inquiring. There are two newer loops there that have some deeper sites that you might want. That's the 700 and 800 loop. If you check each site on Reserve America, it tells you the maximum vehicle length for the site. There are pics of each site here:
http://www.campadk.com/campsitephotos.html?campground=Letchworth&choosesite=yes
2000 Twister by Fifties Trailers,
2017 Honda Ridgeline
2003 Miniature Schnauzer, Meyer