if you want to get technical, if the property owner approves theres is no legality issues. only issue would arise if someone got hurt and wanted to blame it on the property owner, and that can be bypassed with waivers.
but yeah this owuld be awesome. but I agree on waiting another week, get a team to back you, and set up a Op story line, gametypes, and a plan for fun all day play. i will be there from 9am to 12pm if it happens.
and if you need the extra hand Im here happy to help any way I can. I have planned many events in NH and ME.