The language actually prohibits transfer of government money to any state to facilitate transfer of detainees and prohibition of funding to overhaul any building to use for detainment, which was an early plan to rework a standing idle supermax facility in Illinois, I think.
The easiest way around this would be to privately fund the flights to wherever they decide to move the ones we intend to hold forever, since we can't logistically take them to trial, and to use existing supermax facilities to house those we intend to detain forever, some of which we clearly intend to do so with. Over half of the detainees are free to be transferred back to either their home countries or willing third countries. Many of the rest could be tried without much effort, but there are a handful, probably fewer than 20, which we'll never be able to either release, or put on trial, due to the huge amounts of evidence which would be inadmissible due to the way in which it was obtained.