I take it from the complete lack of response, even with Samantha watching, that this is not something possible yet.

 Samantha, please consider this a very strong suggestion for the next release!

Good morning Christopher!

I'm sorry for making you wait! The page at the end of your shopping cart can not be modified, but you can create invisible pages.
So what you can do is:

• Create a researved area with invisible pages (you simply have to click on the ''hidden page in the menu'' icon, above the sitemap creation window in Step 2). Therefore you can either decide who can enter this section or you can send the link to the invisible pages.

Hope this helps!