Here is a drawing of my room basic layout
At the (high) risk of a WAF-related incident, given that room I would actually get creative and see if rear surrounds could be built into the island under the counter.
The side channels seem like they might be difficult to place though. Especially with in-walls in exterior walls.
I think there's a separate question you should ask yourself first. Do you actually want surround and why? What I mean is, what is your reason. I understand you'll have a dedicated room later on, and this is obviously mixed use, so the possibilities for letting it rip are less. For example when entertaining, it's also nice if people are able to have a conversation somewhere.
When that is clear, it's probably also clear to you just how far you're willing to take this. I ask because in your OP it could seem like a bit of an impulse; was thinking of soundbars, now this until that - to paraphrase.
For example, one solution could perhaps be installing the side speakers in the ceilings, but that means no Atmos (you need separation between bedlayer and heights). But that's a compromise to what you're asking.
And at that point, I'd personally ask myself what I'm even doing and simply get good stereo towers or even a 3.1 or 3.0 setup and simply use that.
But my way of thinking is generally pursuing ideals all the time. So in that sense, if I want to make a HT, I'll try to make every aspect as ideal as my competence and budget will allow. That motivates me. So if I have to make too many (to me) unreasonable compromises, I'd simply rather not at all. That's my mind - probably not yours.
I would suggest, while contemplating the question a bit, if you maybe have a setup in your house or maybe a friend's or even a showroom in a store you'd consider buying your gear from, where you could actually test this. I.e. demo some clips or even full movies on a multi channel system, and repeat with the system set to the front three channels only for example.
See if you're actually missing out on anything tangible that is worth chasing.
Just to get a sort off "how much is this worth to me" impression which you can then hold up against the efforts required to get a good solution in your room.
I hope it makes sense, and please know I'm not trying to be negative about neither you or your room. Just trying to clarify a bit.
KR,
Nicolai