AI have to deliver a cake early in the morning and the cake I have is 5 tiers with a floral cascade from top to bottom. Can I fully decorate the cake with the gum paste flowers the night before and keep the cake in the fridge so my buttercream stays firm for next day delivery? It is fondant covered and my first time with a cake like this so I need time to place the flowers the day before as I wont have enough time in the am. Thank you

No!  It will soak up the moisture in the frig and they will fall apart.  Need to get up early enough to place them before the delivery or leave it out all night.

I personally would not put your gumpaste cascade in the fridge.  I've also had heavy flowers/toppers rip out of cakes during transport.  Keep your cake in the fridge and place your cascade on site. 

AIt's my first cascade. Should I have it mostly in one piece, like a swag, and anchor it with a spike in the top styrofoam and curving it down the cake to bottom and securing with another spike. Most of the flowers are wired so I can't just stick them on with icing. Thanks

I understand the feeling of wanting as much done ahead of time as possible.  :-)  Doing it in mostly one piece is up to you.  It's more of a personal preference.  There isn't any hard and fast rules about how you put your floral on...  Gumpaste doesn't have the "give" that fresh flowers do so keep that in mind.  You can have a gorgeous cascade made and then go to place it on the cake and have a real nightmare trying to get it to lay the way you want.

Putting sugar flowers in the fridge  is a definite no-no.

If it is a sponge or pound type cake then I agree the cascade may be too heavy and just fall from the cake when it warms up a little. Far better to make individual swags for each tier then place them on the cake so they look like one swag that goes from top to bottom.

I always send the flowers in a separate box, so that if the caterer chooses to place the cake in the fridge at the venue they won't get ruined, and they are then placed on the cake before it gets taken into the reception.

If you are not going to be around to place the flowers on the cake then assemble the cake with the flowers before it leaves your kitchen, take a photo and send the photo with the cake so the caterer can see how to place the flowers.Don't forget to number the swags according to the tier they are to go on.