It is probably infeasible to make a wide body aircraft the size of a 737 - if they could, they would. The ergonomics (and economics) of twin aisles is vastly better than single aisle planes.
Boeing/Aurora are kinda trying that with the D8 (aka double bubble). It’s not exactly the same since it is basically two circles next to each other rather than one large one, but it will be twin aisle.
The D8 is one of the cooler projects right now, in my opinion. It isn’t too radical like many designs, but it would dramatically lower fuel consumption (50-70%), offer dual aisle boarding on a smaller craft, and a lot less noise. All in a package that doesn’t have too many unknowns from an aeronautics perspective.
