Feeding the yeast cake

I have a Light scottish ale about to come out of Primary, That I used 1056 smack pack on. I fermented this at 65F. I have a barley wine that I intend to put on the yeast cake. What temp should I cool my barley wine too before I toss on the cake? Should I warm the yeast a bit and toss on the brew at 68F? Would it be ok to aerate after I toss the brew on the cake(With aquariam type pump I got from homebrew shop), or should I aerate before I toss the brew on the cake?

I'm having to cool the brew in an ice bath, it may take me a little long to get it down to 68 any problems with taking a little longer to cool down as long as I keep everything clean?
Thanks

I'd pitch at 65F. With a yeast cake aeration isn't necessary and a cooler pitch means it is less likely to blowoff. Clean is the key.