Hi ! I need to make 1/2 sheet tre leche cakes for a wedding. I have only done a couple of small round ones and they kept leaking the milk out from the bottom edge. Do you serve them from the pan or turn them out on a board like regular cake. Do you use stabilized whipped cream or just regular. I also have to transport them about 70 miles at the end of June (northern climate)They only want strawberries for the fruit on the cake. What is tres leche buttercream? I can't seem to find a recipe except for dulce de leche buttercream. Thanks in advance for your help.

That is exactly why they are not good for a wedding cake. The need to remain in the pan
The dulce de leche is the right icing recipe.