I asked that question and explained that I make road trips on paved highways, to get to off-road destinations and drive off-road and that, when off-road, I am always on, at minimum, a two-track...
To be clear, I filled out a Haggerty application, online, and marked that I drive off-road... once I submitted the app, I received a phone call from the rep...
She asked a number of questions. I answered them honestly and she told me, "We are a 'classic vehicle' insurance company. We insure classic vehicles (meaning vehicles that are 'show ready'). We don't insure vehicles for 'road trips' and we don't insure vehicles for "off-road" use. We insure classic vehicle clients who drive their vehicles to car shows, weekly classic car get-togethers, and short trips (like, to get an ice cream)".
That's when I asked what would have happened had I not checked the "off-road use" item on the app... and she replied, "...claim denied, policy cancelled, potential charges filed".
Having read all of the assertions of MUDders using Haggerty, I was a bit taken aback... but... this is my experience with Haggerty.
If you have further questions, you really should discuss it with Haggerty.
I suppose you could always tow it to a paved road and start a claim, but I don't operate like that...
HTH