Hi I am making a wedding cake for next Saturday, the base tier is a 12inch mud cake which is in the freezer.

 The venue has asked for the cake to be delivered on Thursday (they have another wedding on Friday). Due to hosting overseas visitors this next week I am planning on decorating the mud cake on Tuesday, the remaining two tiers on Thursday.

 Questions are, should it be necessary to use any sugar syrup on the mud cake to keep it moist, what ratio cream/chocolate would  hold up best in humidity ( I am in Auckland NZ) and finally I would prefer the cake filling to be a bit softer ganache than the outside coating, how do I achieve this?  Is it just a case of adding more cream, or would you add butter?

Great site, I have learnt such a lot from you all, thanks in advance!