For practicality you're going to have to rent a generator large enough to carry the hotel through the process. These rigs are to be found in Thom Cat or on the web.
While on the generator-set the biggest loads would be eliminated. That is: you'd schedule for good weather and lock out the air conditioning load, etc.
By using a hefty gen-set you've taken the monkey off your back. The Poco pulls the fuses and records the CT readings... While you un-bus their secondaries...
Then you swing into final action with what ever scheme the EE's have come up with. At this scale, my AHJ won't permit an EC to perform the design. So I never sweat it.
With all of the design work and permits -- this project will come together next Spring, at best.
The idea of swinging this project without massive temp power -- doesn't fly with me.
BTW, consider a back-fed tap onto the mains, also. You might be able to rent/ use a second-hand breaker for such a scheme.
This will also have to be co-ordinated with Life Safety issues.
