I havent re-listened to the video but is it possible he's saying they are on a 3-4 month trip rather than they've been on the road for 3-4 months? I believe it would be about that long if they planned to end on Halloween as I've read.
Agreed, people keeping taken words in these videos so literally like its something written in a crime novel and the words were selected carefully by the writer. Its real life, people use idioms and short cuts and such.