I had the exact same conversation yesterday with my Insurer (Elders).
I have just built a shed on a 9 acre block of land, but don't live there yet.
I insured the shed, and asked about contents insurance, as I intend to start moving 'stuff' out there within a month.
They said to hold off on contents insurance until the day you move stuff in, then take out contents insurance, but don't take out too much more than you actually need.
The reason was, that it is expensive to have contents insurance for a shed, when you don't live on the property. As soon as we move out there, it becomes cheaper.