Hi Steve,
You actually have a few options available to do what you are trying to achieve through Method, so the answer is, yes, this is definitely possible. The simplest way, would be to add an action to your WorkOrder screen, so that when the work order gets 'saved' after being marked as completed, you will automatically send an email with the attachment of your 'survey'.
There are other ways you could do this in Method, like create a Method Webform. Your Customers would be able to click a link you would provide them to your web form, they would fill out their comments and then "submit" the web form . When they submit the web form, it would automatically get sent to Method and show up in your database. I provided a link here, describing how to create a "Web-To-Lead" form, however you would have to do some additional customization to create a web form that suites your needs.
A third option, would be to take advantage of your Contacts Portal, a link to get your started on this is here. You could potential create your own tab in your Contacts Portal where you would place your survery. You could send your Customer an email with a link to your Contacts Portal. Your Customer could then log in to the portal, fill out your survey (which would be automatically entered in Method), they could also view their previous transactions and update their contact info from here.
If you want, I can lay out some simple steps for my first suggestion, sending an email with an attached form to get you started with that. If you are looking to do some customization in Method, and aren't really sure where to start, I would advise you to check out our webinar videos on Customization, link here.
-Ben