Indeed, until the day of travel, your recourse is solely with AV and NH will do nothing. The email is incorrect. As your flights were cancelled, you are due a full refund to your original form of payment and, if AV does not refund (fees + taxes), a chargeback is in order.

At a more practical level, if you do wish to travel, you will need to do the research yourself and then propose alternatives to AV. What are your dates of travel and destination?