Where to get warranty work done if Hummer goes under

[Planohummer]

'lawsuit' is the dealer franchise agreement with each dealer--the same one that keeps GM from putting one hummer dealer across the street from another. it deals more specifically with sales territories but the service is included. These agreements vary from state to state.
GM currently lets cad/chev/GMC dealers handle 'disabling' warranty work on Hummers, but you're right-most don't want to touch them.
IMO If/When Hummer gets sold one of two scenarios are likely for servicing:
1)the brand purchaser takes over any and all warranty obligations
2)GM allows all GM dealers to perform warranty work on Hummers. True stand-alone Hummer dealers are in the minority so it would actually work out better(more potential service centers).