FEMA has an enourmous "black bag" budget and it's not open to review by anybody. It does stand ready to assume total control of all gov't operations in case of national emergency like a WMD attack. The Executive Orders are real and were "fine tuned" by Clinton and even Bush 41. There was an EO overturned by the Congress a few years ago that directly threatened the 10th Amendment States Rights clause. That was a Clinton attempt at the end run.
I know nothing about "garden plot" or "cable splicer" or the large camp outside of Fairbanks, but kinda doubt it for the rather extreme weather conditions that would make it hard to guard and difficult to maintain. But it wouldn't surprise me if there was such a camp in the desert southwest. Still a temperature extreme, but more doable.
There is a lot of hokie information about the FEMA camps. Do you know if there is a .gov site that discloses information about them? I found information about Region X at FEMA's site, but do you know where there is legitimate documentation about others?