Can't Play Offline

I migrated my account to a Microsoft when I was prompted to do so, now when trying to play the game when there is no internet connection (Offline) the button says "Play Demo" instead of "Play Offline". It also says that if I want to play the full version of the game, I must log into my Mojang account (which is no longer active since migrating.

I would love to be able to play offline once again, so I can play while on a trip where internet isn't always available, and when I lose internet sometimes.

Thanks.