We faced the same issues prior to our first cross country trip - Ft Myers FL to New Orleans, through Texas, New Mexico, Utah, Arizona, back to Utah, Colorado and then return to Illinois. Our next long trip was Illinois to Montana and back. We loved this planning tool we found online (free and we have no affiliation other than happy planners). Here's a blog post I wrote with a tutorial on what we learned using RVParky.com:
RV Trip Planning Today we're headed from Gulf Shores, AL to Brownsville/Harlingen Texas for a couple of months, then a month exploring New Mexico, then another month in who knows where - Arizona? Likely a stop in Denver on our way back to Illinois to visit our son.
Hope this helps!
