I haven't been able to think of a way of automating a backup. And believe me I've been thinking about it the last few days. Of course I have all the photos on my computer since I took them in the first place, but not the text. If you only want the photos, you can download each one (click on More info and then the download icon). But I want to save the photo and associated text.
After a few experiments, I am using a Chrome plugin called Webpage Screenshot. This lets you take a screenshot of a whole page, including the part that's off the screen. You can then save it -- I'm saving them as PDFs, but you can save them as images. Of course the text is not editable but at least you have a record of it. To save time you can use a keyboard shortcut to take the screenshot. But with over 1000 blips it's a laborious process -- I'm doing a few at a time when I have a spare 10 minutes.
Special note for blips: if you want the comments, before you do the screenshot you must scroll down until the comments show. They don't get loaded when you first visit the page, only if you scroll down.