I believe a native will most always utilize a phrasal verb if s/he knows the correct meaning of it. "to tell off" is not the same as "to scold", and that's why I always recommend my students not to use a phrasal verb, unless they're 100% sure of its meaning!

You’ll probably get a mix of answers because the answer depends on the person, the conversation, who we are talking to etc

"Tell off" is more common, but I think it's also more harsh, so there are some circumstances where I wouldn't use it. For example, we say that parents "scold" or "reprimand" (or even "yell at") their children, but I would be a bit surprised if I heard a parent say that he/she had "told off" a child. As another example, if you arrived late for work, your boss might "scold" or "reprimand" you. To "tell someone off" doesn't sound like very professional behavior. The meaning of "tell off" might be less harsh in the UK. GuideDogSaint is from the UK, and he says "scold" and "tell off" have the same meaning. Greg and I are both from the US, and we both think the words are a bit different.

For me 'tell off' and 'scold' are the same as a verb. Scold seems old fashioned to me so I would tend to use tell off. However, I would use reprimand which is similar too. Generally, I think that in speaking phrasal verbs are more usual.

In general conversation I think phrasal verbs are always preferred. The actual standard verb can sound rather too formal. For example: What time did you get up this morning? OR What time did you arise (from your bed) this morning?