Increasing the number of congressional districts would also necessitate increasing the number of votes needed to win.

Right now, each state has 1 per Congressman and 1 for each of 2 Senators.

538 total with 270 needed to win (50.18%).

So if you add house members, let’s say we do something crazy and double it for everyone:

976 electoral college votes (538-100 because the Senate votes are fixed. 438*2 then add the 100 Senators back in).

Now you need 488 to become President. The problem remains, all you did is change the scale.