There are a few NCAA schools like Northern Iowa, Northern Arizona and North Dakota (I believe) among a few others also that have small, but domed stadiums. Bob Young should get an architect to draw up a plan for a 25-35,000 seat domed stadium with retractable or movable seating sections (maybe even a roof that opens or is retractable too) with a stage capability at one end so it can be used year round for indoor-outdoor events including concerts, hockey and basketball. And of course you want the playing field at max size to be able to accommodate CFL Football and Soccer (World Cup games one day? MLS one day?. Premier League teams on tour?) Presto, you have a facility that could be open 250 days-nights or even more with efficient scheduling and planning. One you can play every major $$$ sport except baseball in.
Would that cost a lot? Probably, yes. But...,, now Mr. Young can get a hotel - restaurant - nightclub - bar - retail complex attached. That means corporate partners to share the costs. Then with (NHL) hockey capability, you also might get Jim Balsillie back in the game as a potential partner. If he has partners it lessens his burden financially. And if the facility pencils out as a surefire profit maker, then you can afford to spend more to build it, in anticipation of actually getting that money back and then some. (Dont laugh, I'm sure the Olympic Stadium in Montreal makes next to nothing at all for anyone. Not to even mention all the money losing stadia we have often wastefully built for a variety of different sports and owners down here in the USA.)
It sure wouldnt hurt to talk to some of the colleges and universities in the States that have small scale Domed stadia. Find out about costs, architects, construction firms, mistakes, things they wish that they had or hadn't done, or included etc
This plan isnt actually what I would personally do or favor were I Mr. Young.*** But it might solve a lot of his problems and make his contribution bearable. Plus he might find every city in the Golden Horsehoe and Ontario Peninsula (except Hamilton probably) anxious to have him and his partners to locate it in their community. He might actually get some cooperation and be made to feel wanted, rather than like a sucker on tap to remediate some contaminated land with no highway access that the city seems to now be stuck with.
(*** I would find a community West or South of Toronto in Southwest Ontario that wanted my operation and build a basic stadium with seating of 35,000, expandable to 50 for a Grey Cup, but not so basic as to be unpleasant for the fans. Just to try to keep construction and maintenance costs down. By building it myself, I get all the revenue streams myself and have no rental expense. Plus, I control it and have no conflicts over dates or usage. My models are the old Expo's stadium Jarry Park and the new Vancouver Empire Stadium, engineered and designed for permanence rather than as a stop gap. I think people would be truly astonished to see how nice a stadium one could have, relatively cheaply with the proper design and planning)