Since no one else has responded, I'll provide some possibly out of date info.
First of all you want to avoid any road in NY and CT with "Parkway" in the name - Sawmill Parkway, Taconic Parkway, Wilber Cross Parkway, etc. All have low bridges, so you don't want to be on them in an RV.
From Wilmington you could take either the NJ Turnpike or I295 north then join the Turnpike near Trenton. When you get to the Woodbridge NJ area you have a choice of I287 or the Garden State Parkway. RVs are allowed on the GSP. I287 is toll free. Both take you to the NY Thruway. Another choice to make there, you can go east over the Tappan Zee Bridge then take I684 north to I84, or take the NY Turnpike north to join I84 near Newburgh, NY. I84 gets you close to Avon.
They are working on building a replacement for the Tappan Zee Bridge, but I haven't been up that way for a while, so can't comment on whether the bridge work is causing traffic problems.
2003 Winnebago Minnie 24F - Ford E-450๐