The election results this year are bad. Even if you voted for the national coalition, I think you should be angry about this year's results because they go against the point of MMP. I have two ideas of how to fix overhangs and make sure the government is always proportional, but I'd love to hear your thoughts on it.
Idea 1, the simpler solution: Just add more list seats. Fill up all the electorate seats, then add list MPs until there are at least the base number of seats, and adding another seat would make it less proportional. Pros: It's simple, intuitive, and makes more sense than allowing overhangs. Cons: There could be a lot of MPs in the house.
Idea 2, STV + MMP: This idea uses STV or some other ranked system to elect the electorate MPs, which would be better than the FPTP we use for them now. But in this case, if an overhang happens, the overhang seat with the thinnest majority would be recalculated with the previous winner's votes transferred. Pros: it works in a better system for the electorates, and it makes for a consistent size of parliament. Cons: It's slightly more confusing for the voters, and calculating the seats could take much longer.