Districts do not cease to exist just because you changed the voting method.
STV - https://en.wikipedia.org/wiki/Single_transferable_vote
You rank your choice, if your first is eliminated the second gets your vote.... Similar to what Trudeau proposed back then.

Mixed-Member - https://en.wikipedia.org/wiki/Mixed-member_proportional_representation
This is also can be mix of many things, but in general: you vote to your district's candidate, and/or to a party/list of candidates. The representatives are a mix of district representatives and the list. The list can be regional, or nationwide. Germany is an example of this.

There are many more, and Alberta, Manitoba and BC tried some for a few decades. https://www.cbc.ca/news/canada/manitoba/manitoba-single-transferable-vote-1.5271771