Did you try this?

1. Hit the "Show Printable Version" button on the Thread Tools menu.

2. Hit the "Show all posts on one page" button at the bottom.

That will make the whole thread show up stripped of any graphics on a huge single page. Then you can

3. "Save as a Web Page" using the drop down menu on your browser most likely located under "File".

What that does is cache the data, and when you do that as long as the cache remains you no longer need to download it through an active internet connection. You may want to experiment with this before going "live" ie. having no active connection, by disabling your connection intentionally to test it first.