The warden question hinges on two things:
1. Font of life specifically states "an effect a save can end"
2. Is dying an effect a save can end?
Since making a death save doesn't end anything (it just keeps things stable), all campaigns I've been in have rule that font of life does not provide an additional death save. When rolling a '20' is brought up th DM reminds them that it says and 'effect a save can end' not and 'an effect a really great save can end'
Since usually if the warden is unconscious everyone else is dead by damage or old age, it hasn't been a problem either......
1. Font of life specifically states "an effect a save can end"
2. Is dying an effect a save can end?
Since making a death save doesn't end anything (it just keeps things stable), all campaigns I've been in have rule that font of life does not provide an additional death save. When rolling a '20' is brought up th DM reminds them that it says and 'effect a save can end' not and 'an effect a really great save can end'

Since usually if the warden is unconscious everyone else is dead by damage or old age, it hasn't been a problem either......