Doable? Sure. Worth it? That depends on how much value you place in the overall experience and what kind of movies you typically watch. If you watch movies and TV that is predominately dialog, a nice sound bar could suffice. However, as mentioned above, even a high end soundbar will not provide the presence and impact of a halfway decent 5.1 system. To use a tortured metaphor (alluded to above), putting a soundbar under an 85-inch TV is like putting bias ply tires on a Ferrari. It’s a mismatch verging on sacrilege. 😱😁
If you like action/adventure content at all, you’d be well advised to go with a 5.1 system at minimum. I’m guessing the fact that you are asking your questions that you’ve not had opportunity to hear a home theater system in a friend’s/relative’s home? The immersion provided by a 5.1 system cannot be understated for action movies. A 7.1 (adding height speakers) is even better if you go with an AVR that supports Atmos. I would think that any AVR that has 7.1 ability will support it by default.
My setup is a marantz AV8805 AV pre tuner feeding into a MM8077 7-channel power amp with the main front speakers powered by my new Schitt Tyr monoblocs. (Previous were PS Audio M700s). It is total overkill for my application as I am not using all the channels available.
For 2-channel stereo listening, I put the pre tuner into “pure direct” 2-channel mode. But it’s nice to have 5.1 for some of my SACDs of Pink Floyd remixed for 5.1. Come to the Dark Side. 😉
Keep in mind that there are viable options for wireless speakers for the back channel if running wiring to them presents a challenge in your open concept remodel.
My 3 cents. Because… you asked. 😁