I know this has been mentioned before, but thought I'd chime in as another user who would appreciate a Sonos portable speaker solution. I'll quickly summarize my use case, some workaround/aftermarket solutions, and what a Sonos solution could look like.
Use Case - Our medium size house on a small lot has a front yard and porch, back yard and porch, and narrow side yard with garden and shed, all places we spend time either relaxing or working or both. The porches have electricity, but not where I would mount or place a speaker, so adding Sonos speakers there requires a 15'-20' extension cord for a temporary solution or electrical work for a permanent install (which would then be an opportunity for theft). The side yard/garden/shed has no electricity and requires a 50'+ extension cord to get power to. A key point is all of these locations have WiFi coverage from the network my other Sonos speakers are on.
Workarounds - I own a number of Bluetooth speakers that I usually use in these cases. I often also have a Sonos speaker playing in the garage. It works fine but is kinda redundant having the Sonos app controlling streaming to the Sonos system as well as another app on the phone streaming to the BT speaker. Since my WiFi coverage is fine, I can string out extension cords to a Play:1 which works. There are numerous companies with portable power solutions which provide AC power: Goal Zero, Omnicharge, Anker, and others. I own a couple of these and they work fine but require carrying a not-light power pack and Sonos speaker out to the porch or yard.
Solution - I purposely use the word "solution" because I don't think Sonos would need a new speaker, just a power accessory. It could have a similar footprint to the One or Play:1, allowing those speakers to sit or nest on top. It could have the appearance of a 1/2-height One or Play:1. Sonos would have to come up with a way to join the Power Base (Power Base One or Power Base:1) and a One or Play:1. The threaded mount socket on the rear of the Play:1 would be an option. Inside the Power Base would be 18650 lithium batteries and whatever power electronics (e.g. inverter) would be needed to output power to the One/Play:1. Conveniently, the power input on the bottom of the One/Play:1 could be connected to an output atop the Power Base such that, when joined there would be no external wiring. The Power Base would have an AC power input on its bottom, just like the speakers do, meaning you can leave the Power Base permanently connected to a One/Play:1 such that you can unplug the cord from the bottom of the Power Base and carry the combo off easily for portable use within WiFi range.
This would fulfill my use case above, but I can think of other uses as well. Simply being able to move a speaker from room to room temporarily without consideration of where an outlet is would be convenient for some. Another example: you could run a 3.1 system for your TV, but for movie night, snag a pair of One/Play:1 speakers with Power Bases from another room(s) and configure (preferably with pre-configured, retrievable configuration/TruePlay tuning in the app) to create a 5.1 surround system without the need to plug in the surround speakers to an outlet.
Thanks for reading. Just some thoughts for how Sonos could sell some additional speakers, plus a new accessory, and continue offering customers an elegant solution for multi-"room" audio.