I just lost my broadband, and am left only with mobile devices with any online access. My main PC is offline - and it seems the newest Minecraft launcher doesn't believe one can have no network access. As I start it, I'm asked to log in or register or choose my existing account.. It seems all three options fail without network access, and I can't pick anything else (there's no UI other than the login).
I can get any software to that PC using a pendrive, or edit whatever locally but I have no way to get it online currently. How can get Minecraft to start?