Using double cream in icing I'm looking at a recipe for icing that uses double cream as the substrate for the icing.

How well will the cream be preserved on a 1:4 (or better, given its application) mix?

Also, how well would such icing set? I'm looking for a fairly stiff mix that will retain peaks; can I expect such with cream as the substrate?
Just simply use whipped double cream only:


add a knife point of starch and a few grains of vanilla per ¼L of double cream
whip it (not too much or it'll turn into butter)
pour into a piping bag
refrigerate overnight


and it'll remain stiff enough so you can create anything you want including flowers: