To move home and take on a much bigger mortgage?

[NameChanger2031]

myself, DH, DS1 (age 9), DS2 (age 7).
MlL and FIL live abroad but visit regularly, as well as lots of other relatives from other parts of UK. We need a guest bedroom.

We live in a 3 bed (plus a tiny office) - DC share. No dining room so only 2 rooms downstairs.
We would like a 4 bed so each DC can have their own room, we would also like some extra living space downstairs.

to move to somewhere we like still within our target secondary school catchment we would need to double our mortgage payments, and it would only just be affordable. So we will be able to manage okay but paying a high mortgage until we retire, won’t really be able to save.
right now, we have plenty of disposable income, and things are not tight at all. If one of us lost our job, we could (just about) manage on a single income.
AIBU to think about giving up a lot of financial safety buffer so kids get their own bedroom?

To be able to achieve what you want now is for you and your family to have the best you can is doable. It all depends how much you want to make the change. Your new house will continue to go up in value, mortge payments can be sought at better rates, meanwhile you will be enjoying more space and living now!

We've just done the same, in our 50s, young DC, living for now. Could have been mortgage free, which I would have loved and didn't want to move just because I loved our old home.

My view of life atm is to live for today but with caution for the future. Xxx