回复：我有I-94的复印件和H1B APPROVE的原件,可以从加拿大回美吗?

I think copy of original I-94 is not enough. You need a new I-94 to enter. Actually if you tell the airline or Customer, you will come back within one month, you needn't give the original I-94 to them.

But you can go to US customer to explain your situation, to see if they can issue a new I-94. But I am afraid if you don't have a valid visa, they can't issue you one.

The 30-day revalidation needs you keep your original I-94.