Well as best I can tell you then. Everything is still on the Families machine. You would have to connect live and get it from there. Once you have it, it should be okay.
The way it works is, If you did it all there, it is still on that account. If you can't hook up live you would have to be on that machine to play.
Part of the M$ system to protect from piracy and such is that connecting live gives them all the info they need to keep things apparent. They keep records. You buy something say on my machine via live. They give it to me and keep records of the transaction. Forever.
If I go to my family machine and play a game, I have the option to load my profile there. I play and save to the Cloud. Then when I get back home, the system knows where I am. On my machine. They prompt me to put my profile back on my machine and I then have access to everything I did on the family machine and I get it back from the Cloud.
To Do! all of that I have to be "Live" or online as it is called. Once all that is done all records are now where they belong and I can play all I want, even if I don't "Login".
You might try saving content from the machine you did all that on to a flash drive and then moving it to your local machine. Not sure if that will move the proper stuff or not.
Easiest way would be to get a short term Gold account and some internet. Get your machine all up to date and have a great time conversing with the family.
Sorry if all this seems busy but thats the way it works. PM me if I can help anymore.
Newest update shouldn't matter as Dawnguard was its own update. I still play and I don't have DG yet.