Hi Red5; I don’t do this, but I hire photographers to fly with me to do photoshoots. Traditionally, I get quoted a rate for the time they’ll actively be working (2.5 days shooting @ $1,500 a day= $3,750). I also pay for their flight, hotel and food. Some photographers will charge a fee for traveling time, depending on the photographer. If you’re driving there, you could at least charge your client the standard mileage reimbursement rate of $0.565/mile and that covers gas and wear & tear on your car.
I basically think you need to get paid for the time you’ll be actively working. If that’s 30 hours over 4 days, so be it. Don’t charge for going out for drinks 
. Charge for your hotel and food, and definitely at least get reimbursed for the gas on your drive there. You could also instead of charging for gas, charge a “travel rate” of 1/2 what you usually charge or something like that. If he’s flying people from all over, your travel bill will be nothing compared to others.
Juan