Best duvet for toddlers?

[sometimesalways]

DS is almost 2.5yo and a tall boy, and quickly growing out of his cot and 100x120m duvet. I would like to replace his duvet with a larger one but not move him to a single bed yet. Is there a duvet that is bigger than the standard cot bed ones, but smaller than a single? The single is too big for the cotbed right now. But I cannot find anything suitable in the usual places... am I missing something? What duvets does everyone use in junior beds?

Cotbed duvet is 120x150.
[[
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cotbed duvet

We have an Ikea one - it's an Ikea cot but presumably the sizes are similar

Just buy a single one in a low tog. It can fold under the bottom of the mattress and then won't be waste in a year or so when he grows.

I used this in a junior bed and it didn't look odd at all.

Highly recommend a 100% wool duvet whether you go for single or cotbed size.

Thanks everybody!

@cheeserolls what a good idea, I hadn't thought about this. It might help him stay covered too.... will investigate!

Easier to buy the bedding too!