Try to be realistic. I know Hubble evokes a tons of nostalgia by all the great science that has come and continues to come from it, but these rescue mission ideas are EXPENSIVE. Lets go forward. The next generation scope will be better. Lets put the money we save from not doing a rescue mission into the next generation, possibly speeding up its deployment and/or make it so robust that "rescue fix it missions" are unnecessary (especially from earth trailing orbit lol).

The only way I could advocate any kind of rescue mission is if someone came up with a cheap mission (and that would have to be robotic, which isn't going to happen because we aren't there yet technologically).