If you have no other income, any income less than the $12,550 standard deduction won't be subject to income tax. However, you must still pay the 10% penalty for early withdrawal if you are under age 59-1/2.
The problem with not filing a return, and just having 10% withheld and walking away from it, is that if you don't file, the IRS will take your information and create a return for you in their computers. You are assuming that if you don't file, the return created by the IRS will be correct and will show that you owe tax equal to your withholding and you are even. However, if the IRS computers don't agree with you, and think you owe more, they will come after you. I would alway recommend filing a return and getting the records officially into their system, even if you don't owe a payment because you had the 10% withheld at the time of the withdrawal.
You won't be able to e-file for free using Turbotax, but you can find other providers on the IRS web site who will let you e-file for free.
https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free
