Often by the end of the week, people in complex positions are well past the point of diminishing returns - pushing them harder may work in the short-term, but it's a recipe for burnout.
It's better to have someone operating closer to their peek performance for longer - even if you sacrifice a day overall.
Burnout's more insidious and pernicious than that - and it takes far more than a few days of rest to get over it.
I think if I were to be fired I would like to take 2-3 months off to build up before I started looking for a new job, but that's only possible due to having some savings I could tap into.
Back of the napkin calculations say I would need about $4,000/month liquid cash to not be in danger. Add another 1 month barrier in and I would need $16,000 on hand to take 3 months off assuming that I got another equally paying job almost immediately.