You have a real problem. You cannot let those wines sit in the back of a truvk for 5 days in the sun and heat. they'll be cooked. I don't know how much you have, but I'd suggest paying whatever it costs to ship them on the plane with you and taking them in an aircondidioned car, van, or truck from the airport to the house. Anbother alternative is to pay for temperature controlled storage in Montral til October or November and then shipping them 2 day air. Good luck.
Just one more sip.