You have a number of threads open on interpolation and extrapolation.
For example.... https://community.esri.com/message/724513-extrapolation
Why don't you go back to those threads and provide some feedback there on what worked and what didn't work.
There is little point in providing more advice since a lot of advice was given there, specifically
- extrapolating is a bad idea in most circumstances
- EBK can't be used for extrapolation
- you have asked about IDW, what is wrong with trying that
I think that about covers it all, so search for threads that you have 'Authored' on the left and read the advise provided first.