Penetrating damp

[TantricShift]

I have a house with all manner of damp problems the worst of which seems to be penetrating damp. The house is old and detached and faces the sea, yes the combination is a winner. It has been badly treated over the years and I come along and buy it without realising quite how bad things were. I think the previous owners did a temporary fix on the knackered render by covering it with weather shield but with all the heavy rain in the last few years the walls are saturated and the effects can be seen inside.

My question is when should I attempt to repair the render? I have been advised to wait until Spring but I am worried that I am putting off a job that should be done before the winter really sets in. Can anyone advise me please?