Speaker set up for more than 1 person

Need to know your speakers. 

As others have said, it's physically impossible with a 2 channel system to have a sweet spot big enough for 2 people sitting normally. I would run a center channel when you have guests over or even for yourself on some music. This way you trade holographic (stereographic) imaging for pinpoint center, flat image. Soundstage can become overly grand but with the right music, the right mood, it's a fun time.

EQ/DSP will almost surely be necessary. Here I would ignore tonality problems and prioritize an even bass response across the sofa

My Sweet Spot is about  + - 5 in. on X axis and 3 ft. Y axis. Speakers are Maggie 1.7i s so Y axis SS is much greater. Wife enjoys the sweet spot too, but is usually content sitting to the side out of the range.

For her to best enjoy her favorite songs, my solution is for her to sit in LP and I sit in LP on floor with her legs on my shoulders. What can I say, it works for us. Of course this position wouldnt be best with friends, lol.

Obviously, setups to widen the sweet spot will compromise the sound as compared to the ideal setup.  I am not saying extreme toe-in will not hurt the sound, but, it would be the easiest temporary compromise for when you are entertaining a small group of listeners.  I have helped with a number of audio show setups, and that is what is employed because the listening chairs are set up practically wall to wall with most listeners WAY outside anything resembling the sweet spot.  If you can, put a low chair dead center between the speakers, and slightly taller chairs close together behind that center chair.  This will deliver respectable, if not ideal, sound.

Depending on how critical you are about what constitutes the sweet spot, that spot can be very small, as in only a few inches wide.  This is the case with almost ANY speaker and room setup with the possible exception of omni-directional speakers (e.g., MBL speakers).  The closest I've ever heard to a system that could deliver a decent stereo sweetspot for two listeners was a giant system (speakers 4.5 ft. wide and more than 8 ft. tall) in a dedicated listening room that was about 25 feet wide by 45 ft. long.