Jill, he will be fine!
He may be fed up for a couple of weeks, but I dont really see an alternative.
I had the same problem last year when I went away for a week, my husband looked after the birds and he cant get them back in the cages.
They were so pleased to see me when I got back and I missed them so much!
I hope you have a great holiday and dont worry about Harvey, its great he is staying with someone he knows and you can trust, thats more important.