I use the RV 760 and generally like it. It does have a few problems with locating campgrounds occasionally, but I rarely use it without consulting other sources. As for the OPs original question, I estimate about how far I want to travel, and then use the Android app "RVParky" to locate campgrounds in the area. It has been very useful. A lot of times, I will have my wife open RVParky about an hour before I am ready to stop, and see where the next several parks are on our route. Then, we will pick one, call ahead to see if they have an opening, and use RVParky to navigate to the campground.
Carroll & Betty Davis
2013 Cedar Creek 34RLSA
2011 Ford F250 Superduty Powerstroke