I will be traveling 2 to 3 times a week for a part-time study program in Toronto while being on my 7th year extension stay on H1B visa in the US. I just got my permanent residence in Canada so I know that I will not have any problem entering Canada. However, will it be a problem while re-entering US considering that my H1B visa stamp on the passport will be expiring soon and I will be commuting frequently? Please advise.