I have just recently been through this: at 4 years into my IVA, with a mortgaged property and having taken the maximum 6 month payment break, so in reality with another 3.5 years to go (due to the extra 12 months payments in lieu of the impossible remortgage attempt required at end of 5 years), I was paying around £128 a month when I had to reduce my working hours from 5 days to 3 due to ill health. My mother in law very kindly offered to help me settle the debt, so we made an offer of £3000 which was eventually accepted, after an initial refusal because they thought I was going to retire due to ill health. To carry on to the bitter end would have cost £5120, but as with your circumstances my ability to pay that had been severely reduced (though in reality we would have found a way) thus making the creditors look favourably at getting some jam now versus risking losing it all later, I suppose.
Now just waiting for the paperwork to come through then I am completely debt free

Meanwhile keeping up the mortgage has meant the property has accrued about £25000 in added value due to rising house prices, whilst the outstanding mortgage has also been reduced by about £25000. This means being able to retire from my stressful job when my work pension is due at 55 and do something more relaxed, then retire completely by age 65, as by that point will be mortgage free