@WSLondon
It is possible but your will need to purchase a 3rd party conversion service to do so. Firstly, convert your data to QBO US version. Then convert to QB Desktop US version and finally QB Desktop CA version.
Another option, you can utilize a migration tool to do so by yourself. I.e TPExporter for Online and TPImporter for Desktop.
https://transactionpro.grsm.io/qbd
