Ah, just curious on what your response would be.
What I have actually been advised for those types of needed liquidity is to actually get a loan through your employer 401k (if possible, of course). Basically, you are paying interest back to yourself and is virtually a way to keep myself invested yet have money when needed for practically no cost.
Of course, they don't give out loans for just anything - so it's not quite that easy.
Also, I keep telling myself there is going to be market correction, so I'm a bit slow on tossing everything in at the moment... I haven't made my 2015 ROTH contributions for that very reason heh.