Last year the most reasonable quotes were coming from, Lifesure, Ripe and Cover 4 Caravans.
We have in the past insured with Lifesure, C4C SAGA [policy prices very variable] and Caravan & Motorhome Club [you now need to take out a mortgage]
Fortunately we have never needed to make a claim, but a little background knowledge that may be of use. I taught at Secondary School level for 35 years. An ex 6th form students family ran a recovery service and yard, including Mayday and Red Pennant Recovery along with a lot of insurance work. The companies I have mentioned above were all well thought of and efficient. [except Ripe who I do not recall being mentioned]

Colin