How to stop visitors from accessing pages behind a cover page while rebuilding strongly indexed site on Fluid Engine

Hello, I wonder if anyone can advise me?

I am in the process of refreshing and upgrading a 7.0 site to Fluid Engine. This is a well indexed site and very popular with potential customers who may have already bookmarked several urls for future reference. 

I have a 'coming soon' cover page fronting the site while we make design adjustments after publishing on FE and I’ve switched all pages (apart from cover page) to 'Hide from Google'.

However, of course, google indexing still shows these pages when searched, see screenshot, so if Engagement rings is clicked then they get into the site and have the potential to purchase. Also if someone has already bookmarked a page, the same happens.

The way I understand it, there is no way to stop this happening as pages are already indexed out there. And while the site may loose traction over time, for now the potential is quite real. My client does not currently want to make any sales as she is taking a breather while the site is in progress and is rather anxious about this but I can’t see a way around it.

Any help would be most welcome.

Adding a site wide password will redirect every link to the lock screen. There's not much you can do with that page in terms of content and design but it will be effective at hiding the content and preventing purchases. This will have a major impact on the site SEO, but so will enabling "hiding from search results" on every page. Minimizing the time the website is "disabled" will minimize the indexing hit. I hope that helps!