Advice wanted please! I made a cake - which has luckily made it to it's venue OK and has now been eaten  - but if anyone can give me a bit of advice for the next time please.....

I made a Chocolate fudge Giant Cupcake - no problem- made these many times before - but it's been raining a lot here and the atmosphere is damp.I  buttercreamed the cake as usual- and had already made fondant decorations which were hardened and went on to the cake fine. Then my problem started. The damp, cool atmosphere which I needed for the Buttercream  made the fondant soften and they became sticky, The only balance I could get was in the fridge with the setting on nearly ' 0' so it was holding the cake rather than chilling it. I made the wired decorations, the train and the plaques from Gumpaste and though that the Tylose powder would stop these from softening - it didn't! Never had a problem before and am wondering if anyone has experienced this - and how you get the balance of keeping both buttercream and fondant stable?  

Hi I don't put gum paste in the fridge cause it tends to soften on me. I run a dehumidifier in my kitchen to help with humidity issues and it works like a charm. No sticky fondant issues.