Go below the frost line as deep as you can! Seal where you go thru the wall really good.
Our pipe here was not sealed too good, so I had to knock it out and do a bigger area around the pipe , but it did stop outside water from coming in.
Our pipe from well to house is about 4 1/2'. 3 outside hydrants are a little over 4' but so far have never froze.

"A machine you build yourself is a vote for a different way of life. There are things you have to earn with your hands."