It's interesting how remixes and/or production changes can alter a song. I am not keen on fan mash ups but this is pretty good:

Alive/Hello:
https://youtu.be/NC9p3H1tXAg?t=1m

Uptempo Mix:
https://www.youtube.com/watch?v=ffk4rot0XF4

I'm not mad on remixes but I quite like these.

Yes heard a Hello remix in a store playing Capital radio and it sounded great uptempo.