I'm with Matt Fradd.
When you tell your kids that Santa comes down the chimney, that he
lives at the North Pole and has flying reindeer, it's a lie. It does not
matter that the intention isn't to deceive, it is deceptive, and it's
objectively untrue.
I don't "do" Santa with my kids.
I told my two oldest that if they want to pretend Santa exists, I'm fine with that.
Neither have taken me up on the offer.
My five-year-old isn't really caught up in Santa. Since we don't take Santa too seriously in our household, she doesn't really think about it.
I want my children to be able to trust me, because there may come a time when it is crucial that they believe what I say. So I refrain from telling them things that are objectively untrue.