"to varying degrees" is correct and can be used in written English. You can use it to describe how something varies in amount or extent. For example: "The students' interest in the subject ranged to varying degrees."
To varying degrees, it succeeded.
That to varying degrees, they have help?
So, to varying degrees, have their wives.
Everybody is happier; to varying degrees.
All four films disappointed, to varying degrees.
Everyone knew about it to varying degrees.
The approach works to varying degrees.
Cornmeal is maize ground to varying degrees – fine, medium, coarse.
All, to varying degrees, are robbed of their humanity.
To varying degrees, other characters come off better.
On Monday it was all those things, to varying degrees.
I love the desktop app, it’s always running on my Mac. Ludwig is the best English buddy, it answers my 100 queries per day and stays cool.
Cristina Valenza
Retail Lead Linguist @ Apple Inc.