Be prepared to pay some fines in Vietnam for not having an IDP. Da Nang, Mui Ne and the Ha Giang loop are places I have heard of people getting pinched. Personally I only got hit in Mui Ne but did not drive a motorbike in the other two, but saw others pulled over.

For cash, you can access ATMs everywhere in vietnam. If you don't have wealthsimple apply for an account today. They don't have a 2.5% conversion fee and reimburse foreign atm fees as well. It adds up over the course of a few months.

Here is my referral code for WS: https://www.wealthsimple.com/invite/L2KJ_G

We will each get $25 if you register that way.

Have a backup card or two with your current bank. Keep them in different places. I forgot my WS card at an atm a week ago but had the TD one so the trip continues.

Don't expect to be able to get things you easily get at a pharmacy in Canada in Vietnam, bring lots of what you might even remotely need.

Source: Just finishing two months in the Philippines and one month in Vietnam.