You claim against your own policy. If your insurers believe they can recoup some money from another party, they will do so.
Your insurer has access to a lot more professional / legal / investigators / assessors than you do.
Insurance saves you the headache of having to go it alone.
Its one thing to decide on ditching your health insurance, knowing there is a public service available (for all its faults) should you need it.
Its a whole other ball game to try and save €1 or €2 per day and take the risk of not only losing your home, but likely the single biggest asset you own.
By all means reduce your cover (not the Sum Insured) by ditching the padding, such as caravan, bikes, freezer, all risks. You could drop your contents cover, but I'd keep it, and perhaps up the excess instead.