Electoral college "points" are just the total of the number of senators plus the number of congressional representatives a state has.

The minimum a state can have is 3, because all states have 2 senators and at least one representative.

The number of senators per state is a constant, and fixed by the constitution at just 2 each. However, the number of congressional representatives is simply a matter of federal law. Constitutionally, a state must have at least one representative (even if it only has, say, 5 people in it) and a congressional district (smaller than a state anyway) cannot have fewer than 30,000 citizens, and the number of representatives a state is allocated must be proportional to the population, but the ratio can be changed by law. After every census congress goes through a process of "reapportionment", which allocates the number of representatives allowed to each state, while local state governments choose for themselves the geographical distribution of the actual districts (and, of course, gerrymandering has been a common problem with that process historically).

Since 1929 the total number of representatives has been capped at 435, where it has remained. Though it should be noted that this can be changed as easily as passing any law, which, as always, requires the approval of the Senate and/or the President.

Since 1929 only two states have been added to the union: Alaska and Hawaii, which were both admitted in 1959. Both states were admitted with just one representative, increasing the total number of senators from the previous 96 to 100 and the total number of congressional representatives from 435 to a temporary value of 437. This allowed both Alaska and Hawaii to participate in the 1960 presidential election, each casting 3 electoral votes. After the census of 1960 and a post-census reapportionment the size of the House was again returned to 435 members, with Alaska having 1 rep. and Hawaii 2 (such that in the 1964 presidential election Hawaii then cast 4 electoral votes).

Coincidentally, the 23rd Amendment was also ratified in 1961 which gave the District of Columbia 3 electoral votes in presidential elections (previously it had none). That set the configuration of a total of exactly 538 electoral votes which has remained in place from then up to the present day.

As mentioned above, much of this is changeable, as it's just a matter of federal law (though it's been in place so long it would be an uphill battle to change). If the House and Senate (and maybe the President depending on the margins in the House and Senate) agreed to increase the number of representatives to 1000 or reduce them to 200, that could happen. If, say, Puerto Rico were added to the US in 2022, perhaps, then it would be guaranteed to have 2 senators and 1 representative. Congress could choose to reapportion early if they wanted to, but it's more likely they would follow the current law and wait until after the next decennial census (in this case 2030) and then redistribute 435 seats to states based on population. Though, as mentioned, if they wanted to they could amend the law and increase the number of reps to avoid "taking" reps from the existing states, at current population levels Puerto Rico would have about 4 reps. If DC became a state it would, at its current population, retain its 3 electoral votes.