Travel Ban: H1B travel from Canada with valid visa stamp on weekends

Hi guys, we have Canada PR and we are planning to move to Canada. I have some questions:
My husband is planning to work in the States on h1b and come to Canada on weekends.

Given the current Visa ban program, will he have any problem coming to the USA for work from Canada (he has stamped Visa till Jan 2022)?

Will h4 EAD be valid after we move to Canada? Or do I have to apply for visitor visa to come to the USA?

If your husband has stamped H1B visa at this time, he should face no issue in traveling to the USA unless the entry is blocked simply because of COVID-19.

H4 EAD can be used only if you are physically present in the US. The card stays valid as long it is printed on its face.