If I have a cake I just carved covered in fondant, will it be edible (still taste good) and presentable in one week?

In one week and even in two weeks. The nice thing about fondant is that it sort of seals the cake against drying out fast. This is even with no refrigeration and even if the climate is not particularly cool. You only need to refrigerate the cake if it has anything perishable in it, like fresh fruit, pastry cream or whipped cream.

That's good to hear- thanks!

My ex husband still has the VW Beetle cake I (and his girls) made him last Fathers' Day. I wouldn't want to eat it. I am a scratch baker, but I knew he would keep this cake, so I made a DH for the car, and scratch cupcakes to eat. I was pretty sure the preservatives in the mix would let him keep it forever.