I wrote ember-codemod-v1-to-v2 to help you get started with converting v1 addons to v2. Haven’t tested it on a production project yet, so please excuse any shortcomings.
npx ember-codemod-v1-to-v2
You can check https://github.com/ijlee2/ember-container-query/pull/151 to see how you might then update the rest of your code.
There’s also another codemod to help you convert v1 addons (ember-addon-migrator) so I hope that, with both in place, more people can help push Embroider forward.