So, I engaged in a preliminary exercise on the site of examining its dimensions.
I then compared those to Comerica Park, Yankee Stadium and Camden Yards.
In comparing, the current foot print is actually smaller than Yankee stadium (just a bit), similar in size to Comerica; but larger than Camden by about 30000ft2
That doesn't seem to create much room, unless the new towers were integrated with zero separation into one of the stadium walls.
You could possibly extend the footprint the west where a low-rise building attached to the adjacent condo exists; but I don't know that gives a critical mass of space, because that site has a shorter N-S cross-section than the Dome.
Even with a modified orientation it would be hard to pick up enough new space to make something else at scale work.
There is the park space to the east, but I don't see that being up for grabs.
That leaves only 2 options, that I can discern.
1) Expand the footprint to the north over the rail corridor.
Obviously pricey and may conflict with a park/public space vision.
2) Expand the foot print south; on the south side of Bremner there is parking and a pumping station that could likely be built over.
However, doing so would either require building over top of Bremner, or bending Bremner further south to add to the contiguous footprint to the north.
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I don't see a lot of practical options for the volume of development being mooted.
I can find space for 1 tower fairly easily, anything more gets complicated and expensive.