Not sure Reagan ‘84 is the answer, but I do know he was the only one to win the majority of CDs in each state including Minnesota. Nixon ‘72 only won one CD in Massachusetts.
It probably wasn't Reagan, as Mondale won some congressional districts that McGovern didn't and performed better in urban areas. I'll look at the 1984 CDs map later and see if I can determine approximately how many Mondale carried.
Now I’m wondering if maybe Roosevelt ‘36 is the answer….only lost two small states. His only narrow win was another small state. Only three more states were even in single digits. Landon did win more counties than Mondale though.
