A deleted estimate can't be recovered. However, you can check your audit log to get the details of this transaction and recreate it based on the instructions that were provided by GlinetteC.
I can see that the Auto-save feature would be a great addition to the current features that we have. I'll be sure to take note of it and pass them to our Product Development team, so they'll consider it in the future enhancements of our Product.
You can visit the QuickBooks Blog to check for new updates and features that we have.