Some interesting statistics:
There have been 50 VPs (including Vance).
Of the 15 VPs who later became POTUS, 7 gained or later gained office by election: John Adams, Thomas Jefferson, Martin Van Buren, Harry Truman, Richard Nixon, George H.W. Bush, and Joe Biden. 7 became POTUS due to death and 1 due to resignation (Ford). Truman was elected after 1st taking office due to the death of FDR so he both succeeded and was later elected so he's counted in both categories.
Since 1888 only ONE sitting VP has been elected POTUS (Geo HW Bush). That's 1 in 136 years.
So using 49 VPs (since Vance hasn't been subjected to an election) that's roughly 14% of VP become POTUS.
So hopefully, short of succession Vance doesn't have much of a chance.