What's the mustachian philosophy on emergency fund to have available in the bank while paying off debt (not investing yet). 2 months living expenses? 3 months? Any perspective is much appreciated...
This really depends on your comfort requirements and your income stability.
Some people stick with 6 months living expenses, the general consideration is that if the income stops flowing, you can find a new job within those 6 months, and not have a hiccup in cashflow.
Others require the account to have a buffer in case of large unexpected expenses come up that require immediate attention: home repair, car repair, emergency familial mortgage payment (sigh). Some of these can't be pushed off on to a CC depending on the situation.
The general idea of the Emergency Fund concept stems from a paycheck to paycheck household situation where a large expense can't be handled well and goes right on to the rolling CC debt (gulp!) as a last resort. If you have your clams all lined up, you don't need to have a large lump of cash sitting around.
Generally, with stable income, you can simply cash flow most expenses on a credit card and pay it off before interest kicks in, others use a HELOC and spread out the repayment as needed. If you have a credit buffer, the need for actual emergency fund money has a bit more wiggle room. So really it depends on what type of emergency you want to be prepared for, and what your plan of action is for drawing from your resources when you need to.
For my own case, I have a small cash buffer account,
with a large CC pool for immediate expenses,
and a taxable investment account for a long slow draw down in case of "forced retirement".