Just grind all the beans you in the niche the morning you leave for the festival. Porlex and impact gun will be doing an awful job of grinding (coming from someone who used to makita his old ceramic burred grinder in the same fashion you describe).
Beans ground 2 days ago in a niche > beans ground badly in a porlex that day. And you even have a niche that will easily swap between ground settings - might as well use it.
Just grind all the beans you in the niche the morning you leave for the festival. Porlex and impact gun will be doing an awful job of grinding (coming from someone who used to makita his old ceramic burred grinder in the same fashion you describe).
Beans ground 2 days ago in a niche > beans ground badly in a porlex that day. And you even have a niche that will easily swap between ground settings - might as well use it.