IOTA. How would I do cold storage?

I briefly tried with the 2.3.0 wallet the other day. I created a virtual machine and tried to run the wallet whist my VM was not connected to the internet. The wallet needs a connection to load.

So, even if you write down the seed on a piece of paper (which doesn't make sense because it's too easy for human error) then at the moment it would still seem impossible to do cold storage of IOTA because in order to get a valid receiving address from a seed you need a connection.

As a caveat, I understand that I must "attach" an address to the tangle before I receive IOTA to it but I don't really understand how this works.

Maybe the use of "attached" addresses only makes it impossible to do cold storage at this point in time?