You've not made any reference to the darkness or brightness of the sky you intend to be observing from. What you'll see will depend more on the darkness of your sky than it will on the binoculars. If you don't have a dark sky (and most people don't), you'll likely be disappointed in your views -- regardless of the binoculars.
Furthermore, there are plenty of telescopes around that can also show M31 and its companions in just as wide of a true field as an "ideal" pair of binoculars.
Here's a sketch of M31 (and M32, and M110) as observed visually -- from a dark sky -- with a mere 1-inch aperture at 20x with a true field of view of about 3.3 degrees:
"Things" were not as bright nor as easy to see in the eyepiece as they appear in the sketch; but all that appears in the sketch was, nevertheless, seen.
Any pair of binoculars (or telescope) that can provide a similar true field of view at a similar magnification will be able to show a similar view -- if used beneath a dark enough sky by an experienced enough observer.
In other words, getting the "best" view will require more than just having the right equipment -- something that most people tend to ignore -- until they attempt that first view and are rewarded with disappointment.
On the other hand, perhaps you have a dark enough sky and enough experience . . .
With all that being said, under a dark enough sky, any pair of binoculars will provide a very nice view of M31 and family. I like the view with my 8x42 binoculars; but my view with 20x80s (3-degree field of view) is preferred. While my 25x100s (with their 2.33-degree true field of view) is even more awe-inspiring and impressive, even though M31 extends beyond the field edges.
I have three different telescopes that can provide true fields of view of 2.6 degrees or wider -- with apertures ranging from 80mm (true field up to 4-degrees), to 130mm (true field up to 3.1 degrees) to 152mm (true field up to 2.6 degrees) -- all can provide some very nice views of M31-32-110 -- from a dark enough sky.
From a dark enough sky, the binocular (or telescope) hardly seems to matter. On the other hand, if the sky is too bright, the view is likely to disappoint -- again, regardless of the binocular (or telescope).