Did my long XC years ago 3 hrs one way, got in just before a big low pressure. Had to sit out 3 days for it to clear, then of course I learned what the weather will do on the back end of a LOW. Beat the hell out of me and my 150, landed 4 times for a breather at alternates. Best aviation experience ever. alternating altitudes for clouds, flight following, alternate airports, wicked winds. All the stuff we would avoid but never learn.
Oh, and it was back when GPS was a gleam in the civilians eye. Charts, pencils, plotters and computers all over the cockpit. Looked like I got ransacked.
Go For It if he signs off.
Oh Yeah, also learned alot about pour planning, leaving late and not packing enough clothes.