Reagan came pretty close in 1984.
He could've taken Minnesota, but DC was probably out of reach.
Likewise, Maine and Vermont actually went pretty hard for Landon in 1936 -- Upper New England was the inverse of the Solid South at the time.
I think our best bet is either 1820 (contrary to popular myth, that one elector from New Hampshire didn't vote for Adams because 'only Washington should be honored with a unanimous vote', but because he thought James Monroe was a jerk -- replace him and you're good), or 1864, if Democrats nominate a Copperhead instead of McClellan. (New Jersey and Delaware were close OTL, and supposedly McClellan won Kentucky on soldier votes.)