The latest software version for the Apple HomePod and HomePod mini (version 15.6) suggests the speakers will make their way to new markets. It adds support for Siri in Swedish and Norwegian, hinting the mini might make its way to Sweden and Norway in the coming months.
If you want to change the default language on your HomePod or HomePod mini, open the Home app on your iPhone. Long press on the white card for the HomePod you want to update. Scroll down and tap on the Settings gear icon. Tap on Language, then select your preferred language.