I'm planning a MFF covered dark chocolate cake with strawberry Swiss merengue buttercream for a birthday party at a park. It's pretty nasty here in South Florida, and I'm afraid that the SMB will not hold up to the heat and humidity.

I've seen suggestions to replace 1/3 of the butter with shortening, but I'm not sure how good that'll taste. The other idea I'm considering is filling with SMB and covering w a chocolate ganache.

Any suggestions, recommendations are greatly appreciated!!

I would do a strawberry white chocolate ganache.

Either a recipe like this http://bravetart.com/recipes/StrawberryWhiteChocolateGanacheGF

or have 3/4 cream 1/4 strawberry liqueur

or just use strawberry oil extracts