Looking at Kobo's site, I found the following item:
What country is OverDrive available in? though I would quibble that it should be What countries is...
You should be able to use ADE to download the books from your library and copy them to your Sage. An alternative would be to use calibre and the ACSM input plugin to download the books directly into calibre and then send them to your Sage. Both of those solutions pretty much require you to have a valid Adobe ID.