Perhaps if you were careful with heating it (do it in a bowl above a saucepan of hot water on the stove) you won't lose too much potency, though honestly I can't say anything for sure. I mean people make mushroom tea which obviously uses hot water, and I believe it slightly reduces potency.
Someone with experience making tea etc will likely be able to shed some more light on how much potency can be lost due to heat, but I'd say if you brought it up to melting temperature slowly and didn't let it get any hotter or stay hot too long, you wouldn't lose any more than you would making a tea.