xwafflesx, will you need to stay on Rte. 20 or will you have any time to veer off course if a place sounds like it might be your thing?  I don’t know of any brunch places.  But a few lunch possibilities might be:
 
1.)  Voss’ BBQ in Yorkville, NY (borders Utica which is north of Rte. 20 off of Rte. 8)
Cash only, no phone but they are open 11am to 9pm (despite the sign from the 2008 review saying 10pm)
http://www.roadfood.com/Restaurant/Review/1342-6043/voss-barbq http://www.roadfood.com/R…w/1342-6043/voss-barbq
 
2.)  The Only Cafe at Rte. 5 & Rte. 31 in Vernon, NY.  Just off of Exit 33 of the NYS Thruway
One of my most favorite places.  Was just there a few weeks ago when visiting family in Rome, NY.  No menu, no set hours, no prices listed but after three visits I have been bowled over by owner/cook Dave Furer’s personality and his food.  If you know you’re going, CALL AHEAD as he doesn’t have set hours but he’ll usually be open if he knows you’re coming unless he has plans to go antiquing!  Below are a couple of Trip Reports with pictures of the place and the food.  You’ll just have to scroll down the page a bit.
http://www.roadfood.com/Forums/tm.aspx?m=431382&high=vernon http://www.roadfood.com/F…431382&high=vernon
http://www.roadfood.com/Forums/tm.aspx?m=475264&high=vernon http://www.roadfood.com/F…475264&high=vernon
 
3.)  New York Pizzeria & Restaurant in New Berlin, NY (Off of Rte.8) south of Rte. 20.  An old favorite of my friend Doug and his family who live in New Berlin.  The pepperoni rolls, calzones and chicken parm sub are all fantastic!
http://www.roadfood.com/Forums/tm.aspx?m=599557&high=new+berlin http://www.roadfood.com/F…57&high=new+berlin
 
Sorry I don’t know of anything closer to Rte. 20.  Hope this helps!  Happy Eating!
 

Ducks in Madison is good. Don’t know about cider and donuts or any regional specialities. Maybe that fish fry place in Skeniatles (sorry about the spelling)??
 
Cheers, John