will they run out with a tape when we check in
The short answer to your questions is no, there isn't anyone who is going to measure your rig at a COE park, nor have I ever had that experience in any park of any kind, anywhere.
The lengths are posted for several reasons in public parks. In the majority of cases that length is the site length or the length of the pad. Since most RVs extend beyond the wheels at either end you are almost always able to hang the RV well beyond the back of the pad, but there could be a tree, a rock, or some other obstruction. Where the enforcement comes is that they will visit you if your RV is obstructing the roadway and sometimes if you tow or towed vehicle does. In such case you might have a problem.
Another reason for the length limits on sites is the width of the access roads, trees and obstructions, and other things that can make it difficult to get into the site and once more the issue is that you do not block the roadway at all and if you should damage your RV trying to get into the site the problem is all yours.
The third reason for site limits is sometimes the roads into the campground. I have seen many situations where the road to a campground may have tight turns with trees and rocks on either side such that an RV might be damaged by hitting them in the process of making the turns. If that should happen the expense is yours and you could be expected to pay for any damage to park trees, rocks, or other things.
In my years I have observed that the majority of RV owners are able to get safely into sites that are listed as smaller than the RV and keep the roads clear. Remember that those length listings are based on the ability of the least skilled RV drivers so the key may be in your ability to drive and park your RV. I am cautious about length restrictions when visiting a park that I am not familiar with in terrain that I am unfamiliar with. On the other hand, there are a couple of parks that I have stayed in with an RV that is several feet longer than the listing many times with no issues at all. Length restrictions are there to help you, not to penalize you. As long as you can use the site and not violate the park's rules the staff really don't care but if you should damage your RV because it is too long for the access listed, you will get no sympathy and little help from the park staff.
