The earliest that you can make distributions for both a Roth IRA and a 401k is 59.5 years old. This is without penalty. You can take the funds out earlier, but not without a big penalty from the IRS.
The funds that get withdrawn from a Roth are tax free, which is because they were taxed going into it. Therefore, the government doesn't care if you ever withdraw the money or not. There is no mandatory withdrawal age.
The 401k on the other hand was contributed with pretax dollars, so they will be taxed as ordinary income when you withdraw the money. As a result Uncle Sam is going to want his money! The latest mandatory age for withdrawals is 70.5 years old. The IRS puts out a schedule that determines exactly what percentage you need to withdraw in order to avoid the penalty.
If you're in an income range to be able to pull it off. I would recommend that you contribute the max amount to both, so that you have adequate funding in that 11 year gap.