If you have an Android device around that could connect to the speaker (or are OK with it only operating when your phone is within range) you could probably use Lannouncer and Big Talker (I don’t have direct experience with this.
For door chime, if you have an Echo you can also connect it to ST and set up routines to trigger announcements in response to device status, either announced directly from the Echo or on the Bose via Bluetooth. (there are also weather alert options available through skills like Accuweather or Big Sky, if you find that easier to configure than the above).