Do most vets have boaring policies for sick pets ?

The best thing you can do is call the vet and ask, not only about what their boarding policy is (I am sure it varies a lot from clinic to clinic) but also whether they think after two weeks he'll be okay to have someone just check on him once a day. My guess is that if he makes it through until your vacation without any repeat incidents, he should be fine for those 4 days too