Sherrie, I would hate to see all those lovely ingredients go to waste.
I have an idea, and I have never tried it, but it might work. Perhaps you could try it with a small amount before doing the whole double batch?
Once, I made mousseline bc and the sugar syrup temp went too high, but I continued and made the buttercream anyway. It turned out very, very stiff, and was nearly impossible to pipe (it broke the ziploc bag) and unpleasant to eat. But if it were combined with your soupy bc, perhaps that might do the trick? I’m sorry to say that I don’t know what the exact temp was, I think it was around 153-4 when I took it off the heat and then it probably went up a bit from there as I left it in the pan and poured it directly into the whites. I now know to just add water and swirl and try again if the syrup gets too hot, lesson learned.
Another thought is to firm it up with something like gelatin or agar. I would use the same procedure as stabilizing whipped cream with gelatin.
You could also try Rose and Woody over on the blog.