WWE in Wrigley Field made me seriously LOL HARD. I live in Chicago and this is one of the shittiest baseball stadiums I have ever seen. Sure, history is one thing, but looking past the history, you have everything else, and everything else is NOT a pretty sight.
I've never been to Chicago let alone Wrigley Field so I'll take your word for it. Probably a better place for it I imagine in Chicago a better place would be Soldier Field.
Here are some other possibilities that come up to me for future Mania events.
Invesco Field- Denver
Qualcomm Stadium- San Diego
Edward Jones Dome- St. Louis
Metrodome- Minneapolis