how can i remove dependents temporarily to do what ifs to see if filing separate or jointly is better?

If you were legally married at the end of 2019 your filing choices are married filing jointly or married filing separately.

Married Filing Jointly is usually better, even if one spouse had little or no income. When you file a joint return, you and your spouse will get the married filing jointly standard deduction of $24,400 (+$1300 for each spouse 65 or older)  You are eligible for more credits including education credits, earned income credit, child and dependent care credit, and a larger income limit to receive the child tax credit.

If you choose to file married filing separately, both spouses have to file the same way—either you both itemize or you both use standard deduction. Your tax rate will be higher than on a joint return. Some of the special rules for filing separately include: you cannot get earned income credit, education credits, adoption credits, or deductions for student loan interest. A higher percent of your Social Security benefits may be taxable. Your limit for SALT (state and local taxes and sales tax) will be only $5000 per spouse. In many cases you will not be able to take the child and dependent care credit. The amount you can contribute to a retirement account will be affected. If you live in a community property state, you will be required to provide additional information regarding your spouse’s income. ( Community property states:  AZ, CA, ID, LA, NV, NM, TX, WA, WI)

If  you are using online TurboTax to prepare your returns, you will need to prepare two separate returns and pay twice.

https://ttlc.intuit.com/questions/1894449-married-filing-jointly-vs-married-filing-separately

https://ttlc.intuit.com/questions/1901162-married-filing-separately-in-community-property-states

https://ttlc.intuit.com/questions/1894449-is-it-better-for-a-married-couple-to-file-jointly-or-separately

To use "what if" in desktop:

Use the WHAT IF tool:

- Click Forms Icon (upper right of screen) or Ctrl 2 (forms view)

- Click on the Open Form Icon

- In the “Type a form name.” area type What-If (with the dash), click on the name of the worksheet - click on Open Form

- You will see the worksheet on the right side of the screen; enter the information right into the form

- To get back to interview mode - click on the Step-by-Step Icon (upper right of screen) or Ctrl 1

It is usually better to file Joint. Joint has the lowest tax rates and the highest Standard Deduction.   And if you are in a Community Property state MFS gets tricky to figure out.  Here's some things to consider about filing separately……

In the first place you each have to file a separate return, so that's two returns.  And if you are using the Online version that means using 2 accounts and paying the fees twice.  

Many people think they come out better when filing Married Filing Separate but they are probably doing it wrong.  If one person itemizes deductions then the other one must itemize too, even if it's less than the standard deduction, even if it is ZERO!  

Are you using the Desktop CD/Download program?  There is a What-if worksheet or you can copy your return to test in or just start 2 other returns as MFS.  Go to File - New.  The Desktop program can do unlimited returns like for testing.

Be sure to first save your return with a name you can tell apart from others.  If you do another return with the same first name it might overwrite your real first return.  So do a File-Save As.