Landlord insurance between let's - doing it up.

Hi
Currently with direct line. For various reasons tenant left 1 may, but we only got keys 12 may. By 21 may,direct line seem to impose conditions such as, water and heating must be drained, ( how much would that cost ?) electricity only on for alarm purposes etc.
so how are we supposed to decorate , get workers in if we are not allowed to provide heat light and water ?
They not seem to have an alternative policy we can go on ?

Thinking of cancelling with DL and going with someone else. Who do you recommend given that doing it up may take a couple of months, then need to get new tenants or possibly even try to sell it ?

So could be empty for a few months possibly - though we would go round regularly to check on it or do work, but not necessarily every day.

Thanks