I would not dream of discouraging someone from running something like this, but you need to take into account many things besides just the game. Planning it as a "regular game day, only longer and with porta-potties" would fall somewhat short.
The need for planning extends to the players, too. If you have trouble getting through a few hours in the field without needing a break to go back to your car for something, you might find it a challenge just to be in the bush all day (nevermind actually sleeping there).
In my experience: when it comes to long milsim-focused games everyone wants to try it, almost no one actually has the energy (or stones in some cases) to get through it.
But everyone should try it at least. It's a great [learning] experience and as mentioned, I wouldn't dream of discouraging anyone from planning or attending such an event.