In my opinion, the more important protection is from improperly wired outlets and low/high voltage conditions. A simple tester from the hardware store and a pocket DVOM can tell you when you hook up if things are ok, at least at that point in time. As far as I have heard, the greatest cause of the voltage fluctuations in the campgrounds are when everyone is using their A/C units and they are all cycled on almost constantly. That is not so likely this time of year.
I have the same mindset as TURBS... My wife was not interested in learing what to check before plugging in and didn't want the hassle if she went somewhere on her own, so a Progressive Industries hardwired unit was worth every penny to me. The popup only had a control board on the furnace so there wasn't much to fry in it so I never bothered.
I would not cancel your trip. Just do like I used to with the popup. Pick up a circuit tester like one of these...
And you should have a cheap DVOM to keep in the camper anyway. You can get both for less than $20.
- Plug circuit tester into outlet using a 30A adapter (i.e. test the 30A outlet not the 15A as I have seen one wired correct and the other backwards)
- Read the lights and if it indicates good, test the voltage...
- Put the DVOM on AC volts and you should have 105-128 volts.
I personally don't like to see as low as 105 but if you aren't running the A/C it would be fine. This is what I did for our first couple of trips before I could get our EMS installed.