Hey: One of my favorite exercises, too.
I start with my set of pilot
charts and model the trip on a day by day basis. Then I model the stores required,
water,
food, and
maintenance. Then I model stowage, weight,
consumption rate and re-stowage following
consumption.
Two things come up. One is that eating and
cooking are resource consumers and the yacht's weight changes a lot over time. The other is that there is a
fuel to
food ratio. Drifting for days is expensive with regards to food and
cooking fuel... maybe more so than burning
diesel.
As for boats. I have delivered
race boats and cruising boats long distances. A simple cruiser is more resilient than a racer/cruiser and
charter boats are unsuitable.
Did you read Kihivas? It was written by Istvan Kopar who later competed in the GGR2018. He did something similar to what you propose.
Have fun...
Norm