I think this flyer is a pretty good example of a similar situation:
http://northernplainsathletics.com/node/1135It's a beginner/advanced split, with all the women lumped together so the field size is big enough, but I'm not sure how many people would be able to race above Cat 4 'cross, which is going to be a continual problem around here until we grow some local riders who actually have licenses.
I'd ask Larry about it, he might have a suggestion on how to deal with that. The Fargo crew are all 1/2/3 or could convert from road to CX (it's a direct conversion except for road cat 5, which still converts to CX cat 4 because there are only 4 CX categories). The problem would be getting anyone up here to race them; Matt Burt is cat 3 road, Logan I think is cat 3 now (Logan?), maybe Jordan?
All that being said, I'd prefer to run it by the books and have everyone race the appropriate category and not surreptitiously bump people up without having an annual license; but that's just me and it's not my call. Not sticking to the rules in a sanctioned race dilutes the worth of having a sanctioned race and gives people no reason to buy an annual license.
Jordan and whoever else is deeply involved in planning, if you want some good feedback from the rest of the riders in town you should talk to Sears. He really wants to see something good happen.