I think a lot of these plans add cross training in as a way to help increase your level of fitness whilst keeping the risk of injury low. I'd agree with cougie, If all you have is 3 days a week running is all you need to be doing if you had more free time and wanted to exercise 5-6 days a week then cross training is a very good idea so as not to over do it with too much running.
In our local paper recently there was a homeless guy living in a tent under a bridge at the side of the canal. Took the council months before they moved him on. If I was tenting I'd be tempted to pitch up right at the start line on Saturday then have my OH move it to the finish line for Sunday night.
My wife has also moaned about what she's meant to do in the morning waiting for me! My response was do what you'd do if I was there. Don't see how my presence would make much difference I'm usually just doing what she tells me anyway. Other than that I said she should take a camera and loads of photos of people at the finish line, she could sell for a fraction the cost of official photos. She's currently contemplating getting the bus to the shores of LN.