The problem with that is that the 1972 election was a personal victory for Nixon, but the Republicans didn't make much headway in Congress. It wasn't a "wave" election.
I would prefer that 1980 be the model. That was a "wave" election in which Republicans swept into Congress in large numbers along with Reagan's victory.
I am thinking 1948 elections.
Truman versus Dewey. All the polls had Dewey winning.
From history.com:
“In the greatest upset in presidential election history, Democratic incumbent Harry S. Truman defeats his Republican challenger, Governor Thomas E. Dewey of New York, by just over two million popular votes. In the days preceding the vote, political analysts and polls were so behind Dewey that on election night, long before all the votes were counted, the Chicago Tribune published an early edition with the banner headline “DEWEY DEFEATS TRUMAN.”