If you look at the interstate electoral compact it’s up to 209 electors approved and 50 pending.
https://en.m.wikipedia.org/wiki/Nati...rstate_Compact
So this means that just 11 ECs need to pass the legislation before direct voting of the president will be law. Some republicans have vowed to challange the constitutionality of these bills so that is still potentially an obstacle.
But if you look at potential states that could ratify this. Places like Pennsylvania and Arizona which are fairly purple would be sufficient Wisconsin would put it one seat shy.
Will these current swing states in presidential elections vote to diminish their power? Possibly, it may be valuable for the representatives of these states not to be has heavily correlated with presidential outcomes.