Something to consider is making an adjustment to your payroll federal income tax deductions. If you are only going to be earning for 6 months, but the tax rate is based on the full year, you should be able to reduce the withholding accordingly. Add on top of that, a substantial 401K contribution and your tax for this year will be a lot less than the rate your paycheck is projecting it would be.
My final year I worked, I went exempt for federal and state income taxes, maxxed out with 100% of my salary starting at the first of the year, and when I hit the limits, I reinstated the Fed and State taxes. At that time of the year, my taxes were based on how much I would earn for the rest of the tax year, appreciably less than what they were calculated for the full year. This is only doable if you have the cash on hand to cover your expenses while maxxing out the 401K limits. But even if you don't, you can borrow from your 401K, say $50,000, and then put your whole paycheck back into your 401K until it's maxxed out for the year and at the start of your retirement, anything not paid back on that loan is just considered your first draw.
****EDIT****
I also don't recommend leaving funds in the 401K after retirement. Some businesses consider this on their ledger in THEIR black column. Meaning; they consider it their money until it's distributed to you. If anything crashes, and the business declares bankruptcy, you might be standing in line with others who are still owed money. I think the law varies state by state on that though.