It seems you do have to have some withdrawal every month. I mis-spoke when I mentioned `annuity' in another post - what comes out is like a MRD, our Blessings when we `hit a certain age.' !.
The TSP folks sometimes have good advice - anyone out there remember what Spaf wrote about his initial bulk withdrawal, then a 4 or 5% monthly when he talked with them about his retirement funds??
Also, using pen to paper is a good way to figure what you are saving by using your house interest as tax deduction vs the amount of interest you'd save by getting the place paid for. Being out of debt is a biggie in these times.
Another thought - considering your age, have you checked with Soc Sec to see about getting your w/d there started now... it doesn't/ won't affect your Soc Sec when you retire - however - that depends on if you switched to FERS or are still CSRS.
You are to be envied if you are in a position where you won't need those funds to fill out other income when the paychecks quit!!

Pulling them would be, for me, the Greatest Boo-Boo I've pulled in my life - as yet....:nuts:
Good luck & God Bless !
Those with The Knowledge you need will be along shortly !!!