I'm probably in the minority here, but am a big believer in the bucket approach with a good amount of cash in reserve. First read about it on M* from Christine Benz, and it makes a lot of sense IMHO.
Guess it all depends on your risk tolerance. With me ER'd and DW ER'ing in a couple of months, we may not have the time to recover (in some cases over history, 5-10+ years) from a major market drop with portfolio selling while stocks are way down. I'd prefer to lower my risk, keep "enough" equity for growth, and have the cash available to pull from in down markets. The trade-off is opportunity cost, but I don't desire to "run up the number" as high as I can get it - but instead to have "enough" to fund my ER. And reducing risk increases the likelihood that a down market environment won't derail my plans..
The other benefit of holding a good amount of cash is dividends, which can reduce your need for portfolio sales to fund your retirement. 3% of $150K is a $4,500 predictable income stream that can cover a good % of the expenses you mentioned.
If your 401K has a good cash equivalent fund option, that'd be a good way to continue getting the tax benefits of contributing to it while still building cash. Unfortunately, most do not and the stable value funds often have low yields and in some cases higher expenses than something like VMMXX that you can more easily buy with after-tax or IRA $$s.
YMMV, and everyone seems to have different opinions on this, but you're not alone in taking the "bucket" approach with your first several years spend covered in cash.
Best of luck!