Also, is there any escape clause once you see the vehicle and before you sign any final paperwork? You say purchase contract so I'm guessing at a minimum there's a penalty for not following through; potentially being its a done deal before you even see it. I think if you've done your research, you should be at a place where you feel fairly comfortable, assuming you've checked out the dealer for any negative reviews.

I once flew to Minneapolis to buy a truck and drive it back to Utah. I didn't pre-pay or sign anything before going out though. They might have agreed to hold it for me once I committed to flying out but that's about it. Then again, that was a 2WD truck in Minnesota so there weren't many buyers (which is why I got a steal). The popularity of your chosen vehicle might affect that. Also, it was a big name dealer.

I don't know if its standard practice for smaller lots to secure the sale differently. Perhaps it is. I'd say it all comes down to how you feel about the dealer. What's the vibe you get? Do all your due diligence and feel it out.

5 hours by car isn't much. If it were me personally, I'd probably not sign anything until I saw it. I'd plan to drive, to avoid overpriced flights on short notice. If the car were still available when I was ready to hit the road, I'd go. If not, I'd keep shopping around.