Help with multi-room streaming with Bluesound

For some years now, I've been using, and enjoying,  a Bluesound Node 2i for occasional streaming on my main system. I play records, CDs, and stream. When I'm doing my serious, audiophile listening, I'm spinning vinyl. But I like the Bluesound, and enjoy having so much music available.

With a new Node about to be released in a couple of weeks, I'm planning to get one for my main rig and move the 2i to my office system. Which leads, finally, to my question:

The house my wife and I bought nearly a decade back now came with in-wall speakers in the bedroom and the adjacent bathroom. Though we've never hooked them up, I've wondered about doing so. Since I would use them only for very occasional background listening, I don't want to spend much at all on anything I might set up. What I'd like would be having what I'm playing on the Bluesound Nodes to play also through the in-wall speakers, if that's easily, and not terribly expensively, done. I recognize that I could get a little integrated amp with two sets of speaker outs and pick up a used (or closeout) Node for cheap and that would do the job, but I'm wondering if I'm perhaps missing something, if there could be an even easier way to accomplish this. If not, can anyone recommend a very inexpensive integrated amp (with two speaker outs) for such a situation? Preferably, it wouldn't be too big and would be relatively cool-running, too, as the place where it could be most-easily located is inside a smallish cabinet that just happens to be near the spot where the speaker wires come out of the wall.

Thanks for any help you all may be able to provide with this.

-- Howard