I am making a wedding cake for a friend at her request (and am now wondering what on earth I was thinking to say yes). It's a boozy mixed berry--sponge--mascarpone/whipped cream layered concoction (like a berry tiramisu). When I've made practice cakes before, they've been eaten pretty quickly so I have never really tested out how long the frosting, which is 16 oz mascarpone to 1 pint heavy cream plus about 1/2 cup confectioner's sugar, will actually last. Do I need to worry about the cream deflating and melting all over the place (if the cake is out for, say, three hours) or will the heft of the mascarpone keep everything aloft properly?
Also, if there are any tips on cake transportation--it's a three hour drive--those would be appreciated too. I was planning on not assembling the tiers until I got to the site. I figure if everything breaks on the drive I can still stick it all in a big bowl and call it trifle :)