If you don't want to spring for a dedicated RV GPS, an alternative would be
GPS CoPilot running on an iPad or Android Tablet. The free version is good. For a few dollars, you can add voice directions. The RV profile goes up to 13', so you still may want to review your planned routing for low clearances using a Truck Atlas or Low Clearance app.
You do need a tablet with GPS chip, not always included with WiFi-only devices. Internet connection is not required, but if your phone will operate as a hotspot, you can connect the tablet to your phone to get on the internet. That gives you access to Google and Yelp with integration of the search results into the program.
I recall at least one person has upgraded to the truck version of the app which adds a bunch of useful function, but is a bit pricey for an app. Still, much less expensive than a comparable standalone RV/Truck GPS.
I tested the voice nav version on my iPad for a number of trips, side-by-side with the Garmin. While I preferred the display on the iPad, I liked the Garmin routing better and found that to be more important to me. But of course I already had the Garmin unit. If I hadn't, I might be using GPS CoPilot today.
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While the Garmin RV 760 LMT has great reviews, it appears to be retired by Garmin. The 760 has been replaced with the RV 660 LMT which the most noticeable difference will be the smaller screen.
The Garmin website leads with the 660, but you can still
purchase the 760 from Garmin, even though they refer to it as a prior model. So apparently they're leading with the 660 but haven't discontinued the 760. And of course it's less expensive to buy it from Amazon.