Late to the party here, and you already have your answer FIREmenow, but I'll play.
When I began withdrawals from my portfolio, the amount of savings, not including SS (my only other source of future income), was 41x. That was 5 years ago. My draw has not changed (not even an inflation increase), and due to market growth, the savings factor is now at 48x.
I do take SS into account, as I expect it to be there, but because I am fairly conservative, my plan doesn't rely on it's existence. In fact, my future spend is very flexible. I have no idea where I will be living, or how much it will cost (I am a renter), and am very flexible in that regard.
Being single with no dependents, and modest requirements, makes the whole business of ER quite straightforward. The ACA helped as well