up to your ears

[Daruma]

Hello.

up to your ears
: deeply involved in something
▪ They are up to their ears in debt. [=they are deeply in debt]
▪ We're up to our ears in work. [=we are very busy]

Can I use "with" instead of in and in?

Thank you.

[Anglika]

No, because the idiom implies that you are in something: a hole, manure, debt, deep water.

[PROESL]

Hello.

up to your ears
: deeply involved in something
▪ They are up to their ears in debt. [=they are deeply in debt]
▪ We're up to our ears in work. [=we are very busy]

Can I use "with" instead of in and in?

Thank you.

I agree with Anglika's assessment of this idiom based on the meaning of "in". However, I think saying "up to my ears with work" is possible and also makes sense. It could mean that one possesses or is accompanied by something such as debt, work, or problems etcetera. Apart from that, I'm certain people use this idiom with "in" as well as "with". It could be that "in" is more common and usual in this expression because it's easier to envision, or understand, in a concrete or physical way what the expression means using "in".