Remortgage or use up savings

saverupper

I am doing work to my house which will cost approx £140k. This is, by coincidence, pretty much the same as my lifetime's savings. I have an existing mortgage of £72,000 at a fixed rate of 2.99% which has another 2 years to run.

I am unsure how to fund the work. I can get a 5 yr fixed rate mortgage at 1.89% but I am getting less than 1% interest on savings so it it worth keeping money in the bank? Additional mortgage payments will be funded by stopping AVCs on my pension (approx £350 per month), but alternatively could be used to replenish savings.

Should I use up all my savings to pay for the work?
Should I remortgage at a lower rate - 1.89% - to pay off mortgage at 2.99%. I can overpay this by £14000 over the next two years then use the rest of pay it off at the end of the fixed term, and also borrow an amount to go towards the work.
Should I borrow an additional amount, say £50,000, use £90,000 in savings and keep a big chunk of money in the bank?
Any other ideas?

Thanks,