If you are doing 2 returns (one for each of you) you would probably benefit by using the Desktop CD/Download program instead of the Online version. The Desktop program can do unlimited returns. It has a What-If worksheet and several other advantages over the online version. You could do test returns. You could do 3 returns, 2 as Single and 1 as Joint to see. You can see and enter into the actual forms. You would get 5 free efiles or print and mail for free.
Check them out!
https://turbotax.intuit.com/personal-taxes/cd-download/Oh, and you can transfer from the prior year online version. And/or Move your online return to the Desktop pogram. So be sure to save your tax returns as the .tax2016 files to your computer from online before Online shuts down in mid October. Then you will have it to transfer into next year.
How to save the .tax2016 file,
https://ttlc.intuit.com/questions/1899645-how-do-i-save-my-2016-turbotax-online-return-as-a-tax-data...
