I notice you are from Vermont. Was the calf born in the cold or snow? Do you know if it was a difficult birth and/or how long it laid in the cold wind (assuming that is the case)? Did the mother get up and get the sac licked off quickly? Have you got it into somewhere warm? Is it's mother trying to care for it? Did it get some colostrum?
I can remember once my daddy taking a calf wheezing like this and holding it up side down by its legs and swinging it back and forth. I also remember him sticking a piece of straw up it's nose to try to make it sneeze. I'm sorry, I can't remember the outcome.
Give it a shot of AD&E, make sure it's getting plenty of nourishment, and give it a shot of antibiotic and a big squirt of probios. Since your vet is unavailable, maybe you could call another one and ask if you could have a dose of nuflor until your regular vet gets back.
This is what I would do. I'm sure others would be more helpful with this.
Alice