Added benefit of a Kamala win now is that she could run again as an incumbent in 2028 and that’s another four years that Alito and Thomas have to survive
The last time a VP won after their President's term was up was George H.W. Bush, and the time before that was Martin Van Buren after Andrew Jackson's term was up (both one-term Presidents, incidentally).
Like you need the combo of a two-term POTUS, who finishes up while relatively popular, and has a VP who is interested in the presidency, AND wins both the nomination and the election.
So Daniel Tompkins. Elected governor of New York in 1807, and re-elected in 1810, 1813, and 1816. During the War of 1812, he took on a military role and personally financed some of the war effort, and couldn't get reimbursed.
The governor election was in April '16, so the VP nom came later.
Served with Madison from 1816-1820, but while the sitting VP, he ran for governor of New York, and lost to DeWitt Clinton. Madison kept him on the ticket, and he was re-elected from 1820-1824.
By 1825, he was broke and a severe alcoholic, dying right after he left office.
VP's who tried to run for election after the President's term was up:
Al Gore, 2000, lost general
Richard Nixon, 1960, lost general
Alben Barkley, 1952, lost primary
Thomas Marshall, 1920, lost primary
Adlai Stevenson (not that one), 1896, lost primary
John Breckenridge, 1860, lost general