I know 100% I would think the same as you, having seen those figures! What’s in the student debt pot if you don’t mind me asking? What’s the interest rate when it kicks in?
The ‘right’ answer would be to use your savings to pay it off before December, but like I say, I wouldn’t be doing it.
I’d throw as much into the student debt pot as I could, then before the interest kicks in, I’d pay all that off it. With what’s left to pay, unless the interest rate was stupidly high, I’d just carry on paying the £250 a month off (assuming that’s significantly more than the minimum monthly payment) and just make my peace with paying the interest.
Having 40k of savings is incredibly freeing and will be more useful to you as a deposit