Ricky the remortgage is possible to arrange, (sounds like a 'future' 6.9% product) but costs quoted for doing the job are way too high. Unless obviously it includes a fee that includes debt negotiation.
Also Melanie has already said that the offer is unlikely to be acceptable to your creditors. The mortgage advisor can not possibly offer advice regarding the success of a full & final IVA.
Without knowing all the details its difficult to offer advice, but as it has already been suggested approaching your existing lender is always a good idea (for a possible further advance), but to be honest, with the details you have supplied thus far, this sounds like a case that my advisors would be telling you that a remortgage at this stage, would not be in your best interest.
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