Legally separated and ex died in 2020

My husband and I have been legally separated since 2016. I filed as Head of Household since I have two qualifying dependents. I have NO desire to file Married _Jointly but TurboTax gave me no other option when I checked Widowed as my marital status for this tax year. Can I just choose Single and file as Head of Household as usual and it be ok with the IRS? 

 

Edited..unfortunately, I do not know if he received a stimulus check or any of these questions TurboTax is asking since he had not spoken to me or his children in two years. So, please give some feedback on that as well.