Sorry I'm into this thread a bit late but I have been away.

The option I have used over the past 5 years is one that runs on my phone and does NOT need a data connection.

It works just like a standard SatNav but you always have it with you. You only need download the country or U.S. states that you need for any trip.

They always have sales going on and the current one is a lifetime licence for the whole world with updates for £16.49, if you want traffic updates as well it's £22.49 but you need a data link for that part of the service.

The company is called SYGIC and you see there current offer at the link below.

Dave

https://eshop.sygic.com/en/