Having Biden Drop and leave Kamala in would be a disaster, but what if they roll double snake eyes, and lost both to the coof? Would that actually be a better result for them long-term?
I imagine on one hand, it'd permanently ground the executive branch for the next four years, but it'd also give them an excuse to stop bleeding political power like crazy trying to cover up for everyone. Any gaffs or failures from the interim successors could just be written off as "They weren't ready for this, they were forced into it, of course they'd make mistakes". Hell, top casualties like that would probably be an optics boon for their whole coof campaigns and associated ventures.
That being said, I'm pretty sure they'd resort to manual blood oxygenation and eldritch rituals before allowing either of them to die off.