Yikes the "engineering/construction" knowledge in this forum is a bit frightening. Is it impossible hell nothing is impossible? Is it FEASIBLE a big hell no to redo the roof of the Fargodome.
You would not be able to phase by phase remove the roof and have anything going on in the Dome while deconstruction is in the process of happening even if there is no active work at the time of said event(s). No construction company is going to have that liability hanging over their head.
The main roof structure of the Fargodome is held up by 2 very extremely large trusses, and a couple of smaller large trusses between the columns, so no you can't just remove 1 corner post and the rest of the building is fine. You literally would have to deconstruct the roof backward of how it was built. Rip off the roofing, insulation, metal decking, and "smaller" joists, and remove all the catwalks/wiring ductwork and other stuff running through the roof. Then you can start on those 4 trusses that are supported by the 4 main columns that cause everyone so much heartache.
Oh, keep in mind there are only a very very small amount of people who know how to do this properly and safely since you're trying to keep the "integrity" of the rest of the Fargodome from essentially top of the walls (seating) down. So whatever it would take to BUILD a structure like that might as well multiply that schedule by 2 if not more because of all the safety aspects that need to be addressed for the workers deconstructing. After stuff has been loaded up it acts differently than it did when it was built when you start taking loads off. I'd say 1-2 years is the minimum it would take just to deconstruct the entire roof.
So any intelligent guesses as to how much that would cost?! Paying people to work twice as long as it took to build it, at much higher wages (than even today's typical construction worker for building is) due to specialty workers needed to perform this work, and you haven't even started building the new roof yet. Even if you did the Pole Barn cover concept. You might as well take that money and dump it on El Chapo's outdoor stadium because it would be much more "wisely" spent doing that.
(I work in the construction industry, if you want to discuss this more in depth send me a PM, or if you want to question my knowledge feel free to as well!)