Having read all the comments, I have to agree with Pete on the course and his thinking.
I have never run a marathon before (done a few halfs in the last few years), so at 54 on race day I thought it was time I did one and the Guild series includes the marathon. I am born and bred in Preston so I understand what the Guild is about, I remember doing the schools play on Avenham park in 1972, the park was full of people. All week the town was full of people watching or participating in Guild activities. Going back to the Guild marathon, being run at the end of October (not Guild week), people may have forgot about the Guild by then, but a reminder to go and watch in the sticks will not get them out.
If the main sticking point is the traffic being stopped for a few hours, big deal, it is a once in a 20 year event. Preston gets grid locked every week. During Guild week roads will be closed, therefore another day won't be to bad.
I know there is a lot more to organising a race than just planning the route, but lets not take the easy option as a token gesture.
I have no knowledge of the volunteers meeting, I assume this is a group of people who are going to help the Guild to be a success, if so, please listen to others opinions and ideas before making the final decision.