We bought our first 5er from a dealer in Casper, WY. We were young and inexperienced. We went to Casper (around 280 miles away) because the dealer that was close to us was a pain to deal with in the sales department.
What we should have found another brand of RV. The one we bought was a POS, and the servicing dealer was either inept, or constantly put us at the back of the line because we didn't buy from them, or both.
We had major problems, stuff that I don't think most would want to fix, even if capable (shackle holding an axle on broke on both sides, aluminum siding came off the sides, bad window needed replacing, furnace needed to be rewired to the thermostat, the list goes on and on).
Our next trailer we bought local from a better dealer, and were very happy with the support.
If I were to buy again from a distance, I would look into the independent shop as suggested. I'd also get everything done before I got to the dealership - have my financing in order, hitch and wiring installed, everything so I could get in, check the RV out, and get home without spending the day (or in our case) the weekend up there.