Insurance is not a problem.
I ferried my 'gounded' aircraft legally. Grounded due to an MPD issued by the CAA. You need a 'ferry permit'* from the CAA, once you have that (with whatever conditions are applied) the insurance people are happy for the flight to proceed - after all the regulator has approved it.
* the paperwork was I think actually called something else - but we, CAA and I, called it a ferry permit - 'cos that is what it usedto be!