At work we made a c# gh node to read objs directly into grasshopper as meshes. I can’t remember what code we based it on, but after a quick Google it was probably this or this
Both have an MIT license
I imagine you could do something like this to download your file to a temp location, then read it in with one of the above libraries.
Or just point toit locally in google One.
Sorry that’s not a full solution (I’m not at a PC) but it’s some clues If you are willing to try c#