I have 3 days to go before the cake needs to be iced and finished. The marzipan has had a week to dry but is oily because of the hot and humid weather.  I need to fondant ice the cake and decorate it urgently.

Does anyone have any ideas?

AWould covering in modelling chocolate work? I haven't tried it so I don't know if it'll just slide off but being oil based it would be less likely to spoil in my opinion?

Could you try a drier mix of marzipan and recover or even over cover?

Try adding a little bit more powdered sugar to it