Help! -winter boots for toddlers ?

So we have a kind of unique situation that makes shoe shopping extremely difficult with my LO.

He has very wide feet (for shoes he wears stride rite W shoes). He also had one foot that’s hard to straighten when putting on shoes due to cerebral palsy.

I cannot find a boot that I can get on his foot because of the combination of those two things.

But winter is coming and he adores being outside so he definitely needs boots!

Has anyone seen taller boots (that I can tuck snow pants over) anywhere that unzip down the front like this? His stride rite shoes work because I can pull the tongue all the way down to the toes to slide his foot in

Tia !

Editing to add that hes 14 months in a size 6