Looking for advice on the best way to share some content, but not all

Hey gang - I'm hoping I can get some advice from the community.   Here's the deal:  I've been running a weekly homebrew DnD game for more than a year now.  We've accumulated probably 50+ maps and at least twice that in terms of handouts.  To avoid burnout and give me time to do some prep on the next story arc, I'm going to swap seats with one of my players who will take over as the DM for a few weeks.   Let's call this period the interlude story arc.   For the interlude, those of us playing are all planning to create new characters who will inhabit the same world as our 'main' characters and this story will expand a bit on our established lore, settings, etc.  Once the interlude is done, I'll be back in the DM chair, and we will continue the long term campaign in the same world.   So....here's my dilemma:  There's a ton of maps, handouts, NPCs, etc that I want to make available for my stand-in GM, but I don't want to give it all to him since we will ultimately be picking up where we are now.  Because I don't want him to see everything, I don't think adding him as a GM to the game since that gives him the keys to everything.   My first instinct is to clone the game and everything in it, and then take the time to strip out the stuff he doesn't need, but I'm wondering if there's a better way to do this.   Any thoughts appreciated. 

If you trust the interlude-DM not to seek out spoilers for the main campaign, you can archive certain map pages, characters, etc. for later restoration, and/or stick spoilery handouts in a temporary "John's Eyes Only" folder. If not, your clone-and-delete plan may be the way to go.

If you can't fully trust your sub-GM to not look into folders that you label "DON'T LOOK HERE", there's no way to 'lock' folders from other GMs.  So the best alternative is to clone the game and delete whatever you don't want the other GM to see.

The easiest would be if you could swing a month of Pro Subscription. That would get you the Transmogrifier, which would let you drag over just the things you need to give them. And you could do it over time as they ask for more things. Doing it the other way is sure to take hours.