Using Encounters from one Module in a different Module

I started with the Lost Mine of Phandelver.  My players asked if this would continue into another module.  I decided that Storm King's Thunder would follow.  I picked up Storm King's Thunder in the Marketplace.  I'd like to add an encounter from Storm King's Thunder to Lost Mines of Phandelver to do some foreshadowing.  Is this possible?  I don't seem to have access to the module items in either the marketplace or my library, so now what?

To cherry pick items from one game and put them into another requires the Transmogrifier, a Pro perk. If you do decide this is worth it, here is my tip: Make sure the monsters used in the encounter are transferred first, either by the Transmogrifier, or via a Compendium drag. Otherwise tokens will lose their association and become unassigned. This makes the new offering from the Marketplace, the Tactical Maps Adventure Atlas really useful, as the scenarios can be dropped into any campaign. I wish it had come as an addon, but that would have been 22 addons, so...

Addendum: If you don't want to upgrade your sub status, it might be easiest to just create the Storm King's Thunder game and invite the players into it, moving their character using the Character Vault and moving them back later. This is something even a free user can do with a Marketplace module.

Thanks for the clear advice about some of my options.  I decided that since I'll be making use of the SKT, and the Character Vault is pretty easy to use, I would go with the option to start another game and invite my current players into it.  We'll bounce back and forth a bit, as needed.  Ended up grabbing some google pics and creating a couple of handouts because we got to the encounter I wanted at the end of a game session.  I just needed an intro/teaser for the encounter and I wanted to give the players time to update their characters before we moved them around a bit.  So the ability to make a handout in seconds was all I needed that week. Nothing ever goes quite as planned, but the Roll20 features helped me adapt to the needs of game play pretty quickly.  I'm confident and looking forward to the next game session!