The problem with doing it with proportional voting is that you need every single state on board; any state still doing winner-takes-all has much greater power.
Additionally, as long as that proportion is significantly high enough (say above the 66% mark) the two parties that were partially disenfranchised would still be left sharing a strong majority in the house between them and, if something similar happened with the senate, they could coalition up and force through a congressional amendment that would bring the remaining portion of the country in line for the next election.
The Interstate Voting Compact couldn't be precisely similarly applied to congressional elections, it'd need more momentum behind it, but there is a way for the math to work out.
All that said, IANAL and I have no idea if the legal shenanigans used to make the IVC binding could also be utilized for a similar movement around the house and senate.
I'd really like to see the US have regional and balancing seats in congress - the former tied to districts and the latter allocated to maximize the correctness of the representation - so maybe the Purple wins all the races in Maine but Green had 40% of the vote in both races - Green would gain a non-regionally tied house seat[1] while purple gets both of the regional seats.
1. Potentially seats depending on how national elections go