It was always sung as "and we'll" until 1983 when it got changed to "to" as we were physically going up 'to' Wembley. For some reason it never got changed back, even though 'going up to win the Cup' doesn't actually make any sense.i don't know anybody who sings it this way - always thought it was 'to win the cup' and always sang it that way.
personally wish we'd sing 'you can tell them all that we'll stand or fall...' - good to hear people given the full lyrics an airing recently - hats off. it's a great song and the fact is has the line 'Now let your hearts be gay' is frankly hilarious
But I agree with you, "tell them all that we stand or fall" is much better.