Manager in Bank, probably he has advanced degree and already settled in Nepal and i guess he is close to 30s,
He need to start from 0 in USA, so probably very tough for husband to settle in USA with good profession.
Wife BN degree may not be equivalent to 4 years degree only US recognize Bsc Nursing (plus two and 4 years college) so she may not qualify to apply for Master Program. Start from under gradaute/ F1 status dependent husband it will be very challenging for both of them (financial and other aspects).

I believe canada is good straight forward PR , nursing easy to get job, and husband can run small business or study.

I do not know which option is fit for them it depends....

Good Luck to western world.