Hi there! I know it's been a while and I was wondering what you ended up doing? I'm in a similar situation and thought I could recreate the client's site in a new trial site and then switch over their domain but I think they'd have to pay for hosting again or create the site and then take time to manually transfer it from the temp site to their current site which would require their site to be offline (as you mentioned) while I make the changes. What worked for you?