Here are some of my opinions which may help you figure out AWEN’s risk tolerance is.
1. Sleep: You have to trust your partner to judge themselves with their sleep. Telling them what to do is not kosher.
2. Water: I would figure out what your minimum water requirements are for your next destination and never to have less than that on board. I know I’d be fine with 4 gallons per person per day.
3. Fuel: Same as water. Have enough to run your motor for at least a certain percentage of your passage. Decide and discuss what that amount is for AWEN. For me 30% is enough. I am a pilot, and when I fly I always have enough to reach my destination plus another 45 minutes of fly time.
4. Batteries: This depends on your batteries. I assume you have lithium batteries. They do not like to always be full, so discharging them is not a bad idea.

I’d suggest figuring out now what the limitations are for AWEN and put it in writing. Once you’ve learned your boat you can change them, but initially I‘d suggest keeping it conservative.
Just remember Stephan, it is your job to make your crew feel comfortable. If they are uncomfortable you are not doing a good job of captaining. You are cruising, so load a little extra since a few extra gallons of fuel and water will not kill your speed too much. Safety should be your #1 priority in any decision making on passages and especially ones like an Atlantic crossing on a brand new boat. Phew!