Do I Change to a Fixed Mortgage which will cost me more in the long run and increase our term

Brokenskew

My husband and I are worried about what Brexit will do to our finances. Our worst nightmare is that interest rates will surge. Thus, we want to consider a fixed rate mortgage. If we took the fixed rate mortgage deal our bank is offering, this would be fixed for 5 years and will significantly reduce the amount we pay monthly. It would give us peace of mind over interest rate rises. Our mortgage is through our bank, and we have been paying it for 16 years.
Currently we have 10 years on the mortgage, this will rise to 16 years if we take up the bank's offer. There will also be an additional £10,000 to pay off over this time.
Is taking this mortgage deal for peace of mind sensible?
Should we be looking at other mortgage providers?

getmore4less

What rates are being offered.

Why only 5 years why not 10?

Extending the term makes the payment smaller because you pay off less capital that hides the cost of the interest changes.