I'm sorry for your loss.
When you transfer your return from last year, right at the beginning TurboTax asks if anything has changed. This is where to let TurboTax know that your wife passed away. Then, TurboTax will let you know that your returns can't be prepared together this year and give the option to separate the returns.
Here's how to start a new return: https://turbotax.community.intuit.ca/replies/3288128
However, since she had passed away in 2016 (as filed last year, 2017, for the 2016 Return), I was unable to proceed forward with the change for the 2017 return - the date preceded the current tax year. I've attached the error message to my original post.
I appreciate your help and thanks for your assistance.
To transfer just your return forward, breaking it apart from your spouse's, select the option that you lived apart at the end of the year and that your marital status changed. Then, when you select Continue, TurboTax will give you the option to transfer your return apart from your spouse's.