Tonight I began a new courier, and instead of taking the traditional route I decided to go straight up the I-15 north to New Vegas.
Just a quick question: if I do ring-a-ding-ding (not planning to for a little while yet) and meet vulpes outside afterward, inviting me to meet Caesar, if I later go to Nipton will he be there still? Or will it glitch? Will I even be able to say 'you again?' to him in Vegas?!

P.s off topic, but have never quite realised how ridiculous the credit check is to get onto the strip... 2000 caps at level 4? ...

You won't be able to say "You again," but he will be there in Nipton.