The sooner all borders are open without restrictions, the better for everyone.
Whatever CA or the USA decide to do won't last long. Bureaucrats will not give up control and will lock down again. Canadians better escape while they can. Otherwise be prepared for another cold winter.
Besides the delta variant, public health officials will discover the epsilon variant, much more contagious and deadly than the deadly delta variant. That one will require lock downs and completely new set of vaccines.