I think Woodlands Stadium is now out of the question - land owned by CCC within their planning realm.
Warwickshire Gateway (aka Whitley South) is in Warwick District, but i believe the land is owned by Coventry City Council, who might not want to sell it to SISU (certainly not at a bargain basement price, for fear of legal action for State Aid!!).
Brandon still hasn't been settled, has it? Rugby District, privately owned
Land behind Warwick Uni's new Sports Hub - Warwick District, Uni always likes partnerships and owns that land. Posh local residents would probably object, transport links atrocious until they finish HS2 - maybe they'd put an HS2 station there - but it'd probably be served by a one carriage bus conversion!