Offline/separate computers

OK, so this is more of a question. I live in a very rural area in Canada, and I do not have an internet connection in my home. In the previous launcher, I downloaded each launcher for my iMac and my gaming PC (from my workplace), and from then on i simply brought the updated minecraft.jar file home on my flash drive. Is there a way I can do this in the new launcher? The iMac is used for LAN games, so is there also a way to make separate names for offline profiles?