Would have won Maine and New Hampshire, and taken the following counties (as well as all the counties that Trump won):
Maine:
Waldo
Lincoln
York
New Hampshire:
Merrimack
Vermont:
Orleans
Franklin
Rutland
Connecticut:
Tolland
I think Plymouth, MA would be a toss-up if Kasich had been the nominee. he could've won it.
Kasich probably would've held on to the rich South Shore towns that went for Romney but rejected Trump by huge margins, and it's likely he'd do better in them as well, which definitely would've been enough to win the 10,000 votes needed to flip it.