So to pull this approach off you need to have commitment from the sponsor and access to the right people - top down.  Know the stakeholders and discover thei right hand men and women.

And the soft landng of no network access shuldn't stop you.  You have your own computer, and a pen and notebook. Probably your onw email addrss also where you can get data sent.

Of course you can't always pull this off.  In some instances you'll be five months in and still not know who the project sponsor is.  Different gigs, different challenges.