Have been to Mid-O over the years for many DEs but not specifically for Vintage so take my comments w/ a grain of salt:
Though a bit pricey at +$25/day, the hospitality/lunch would be worthwhile... Mostly as matter of convenience unless you want to brown bag. FWIW, course / facility is about 4 miles outside of Lexington, OH and another ~10 mi or so from I-71. In other words, your alternatives are limited as it is a quaint mid-western town.
For dinners your options for chains (Applebees, etc.) are sufficient out by the interstate/hotels. Personally, I prefer finding and supporting local restaurants. A local Mexican joint was decent enough to put down more than one night but last fall they were closed. We did find a nice wine & tapas joint in a strip plaza close by called Happy Grape or similar. Chum up w/ the owner/bar tender (Mike if memory serves correctly) and you'll be well taken care of. There's also a sports-bar next to/near/connected w/ go-kart rental facility (Rocky's?) that I hear is decent but cannot personally attest to.
You should be allowed to meander in paddock when track is cold - doubtful you will be permitted to do so while hot. Mid-O is a spectacular road course and the track is in good shape. The facilities however are getting a bit long in the tooth.
Have fun and remember your lawn chair, suncreen and bug spray!!
