Pull Date from Previous Cell Unless blank, then pull from the next date to complete formul

Hello,

This is my first post on here sorry if I'm not clear.

What I have is a schedule. In this document, I have multiple formulas that are dependent of one of two dates. For example, I have a new store whose dates need to be populated by the date provided in the Soft Opening cell. This store has a grand opening as well. Then I have a store that does not have a soft opening but has a Grand Opening, and the dates need to be configured off of that date instead.

Is there a way to easily say, these dates are based off of the Soft Opening date then the Grand Opening Date if there is no Soft Opening?

I have a attached the file.

Lindsey