Changing shoes during a marathon

MinimalistShoeAddict

Next Sunday is my first marathon and I really want to wear my Vibram Bikilas as planned. However my feet themselves get pretty tired by 20 miles (my longest training run) and I believe my form deteriorates somewhat at that point. I want to stick with a 0mm drop shoe but I feel like I could use some more support/cushioning late in the race. I have only been running about a year but have been using 0mm drop shoes for 95% of my training. I do own a few pairs of 4mm drop shoes I wear on occasion (Saucony Kinvara, NB Minimus etc).

I am thinking of wearing my VFF Bikilas for about 20 miles at which point I will have someone throw me a pair of Merrell Bare Access Shoes (0mm drop shoes with Vibram soles but extra cushioning) to wear for the last 6.2 miles. Am I crazy? Anyone else change shoes mid race?

My second option might be to wear my Merrell Sonic Gloves for the entire race. The Sonic Gloves are somewhere in between my Vibram Bikilas and Merrell Bare Access Shoes in terms of support. I wore them for my first half marathon in January. That being said, the majority of my training has been conducted in one of my Vibram shoes. In fact I probably have put more miles in barefoot this year than in any non Vibram shoe individually.

Thanks in advance for any thoughts/advice!