I don't think it's really usable, honestly. I think there would be a LOT of "is old" and "I sold" jokes. I know any name can be teased but some names just make it too easy. I love Isadora though if you'd consider that option.
I think it;s really beautiful, but I don't think it's really too useable. A little too unusual, maybe. And I can't help but imagine a kid would be teased for it sounding like "is old" or "is older." I dunno. I really think it's a beautiful, classic name, and I love it, but there's no way I'd use it. Maybe, just maybe, as a middle name if I found first name that fit REALLY well.
The spelling of Isolde looks good to me, especially with the 'I' - beginning. But I don't like the english sound of that name. In Germany we pronounce it like this: E (like the letter in the alphabet) - Z (like in zebra) - O (like in oven) - L (like in Lion) - D (like in Derek) - E (like in elephant). I like the german pronounciation a lot :p
Sorry, I don't think it's useable. I don't personally like the sound of the name and I think kids will likely pick on anyone named Isolde.
It's nice. I vastly prefer the Isabel/Elizabeth family for a way to get to Izzy, but I do think Isolde nn Izzy is adorable, and Isolde is very striking and gorgeous. I do have to say, it's too much name for me, though. But I've come across enough people using it in the internet world to feel like it's usable.