I've booked in a Canada trip in January 2020 and I'm flying directly into Canada from Australia. My Canadian Visa is still valid but I dont currently have ESTA for the USA. I'll be spending a few days with a mate in Vancouver and was considering a side trip to ski Mt Baker. How much of a hassle is a border crossing via car for a day trip? Can I just spend my $20, get my ESTA and drive through or is there more to it?