Changing from TD to H1B status question

You guys have told me I can fly or drive across the border and re-enter with my H1B approval in order to change my status from TD to H1B once my H1B is approved. When I was pricing airfares to fly from Atlanta to Montreal or even,Toronto, later on in January, so I can re-enter, I was shocked at the prices (700$ and that's with advance purchase)..... I realized it would be cheaper to fly from atlanta to detroit, then rent a car and DRIVE across the border into Canada and later re-enter by car with the H1B. So when I am in TD status, who do I surrender the I-94 to? The people at the Atlanta airport or to Canada customs as I exit the U.S, or do I give it to the Border guy when I cross back into the U.S??

At any point, do I say "I am relinquishing this I-94 because I have received my H1B approval and will be re-entering with it?'" . Don't you have to say why you are relinquishing it?

I would just keep the I-94. The offcier will sort things out when you present your H1 paperwork.

One should really only relinquish I-94 when they are leaving US 'for good'.

okey-dokey...thanks so much for all the info...we are moving tomorrow so here we go!