Best answer by Keith N
Allow me to clarify. While Sonos will support SiriusXM playback in Canada, your Sonos One relies on the Amazon Alexa service to access the content. This means that in order for you to use Alexa to access Sirius XM, the service needs to be supported by Alexa.
From what I remember, the only services supported by Amazon Alexa in Canada is Amazon Music, Spotify, and TuneIn. For more information check out this part of the Amazon.ca website.