Iosevka font has an awesome looking Interrobang. See https://be5invis.github.io/Iosevka/specimen.html (scroll down to the U+2030 row; ‽ is U+203d).

I think that other fonts should follow that example too.

Until then, as I anyways use subsetted fonts on my blog, I can easily specify the font to use for the ‽ glyph.