My only concern would be the lack of hydration, but sounds like you had that under control. The Intermittent Fasting group on facebook led me to magnesium supplements during long fasts. Maybe you need some potassium too as you could be running out without the nutrients.
Another possibility that I've read about is using bone broth. While they do have some calories, they are generally very light and won't take you out of ketosis while providing a good source of needed nutrients.
If you aren't a member, I'd recommend the intermittent fasting FB group. You'd get a much larger sample of folks who are a lot more dedicated to working out than I am.
https://www.facebook.com/groups/KetoIF/