By default, presets, templates, external editors, and plugins are shared among all catalogs on a computer, as are the settings stored in LR's Preferences. So your new catalog will automatically get those.
The settings stored in LR's Catalog Settings are specific to each catalog, so you'll have to recreate those. There's not many -- just take screenshots of the three tabs and duplicate them in the new catalog.
Smart collections are stored in the catalog, unfortunately. You can transfer their definitions to a new catalog by right-clicking each collection in the source catalog and doing Export Smart Collection Settings. In the destination catalog, right-click any collection and do Import Smart Collection Settings. You have to do this one by one, so if (like a few people) you have dozens of smart collections to transfer, it will be tedious.
You'll have to recreate each of the Publish Services you're using in the new catalog.
Another approach is to make a copy of your current catalog folder. Open the copy in LR, select all the photos, and do Photo > Remove Photo. Be sure to select Remove and not Delete From Disk. Now you have an empty catalog with all the settings of the original. Personally, given that your catalog has hundreds of thousands of photos, I'd prefer creating a new one from scratch. Decades of experience has taught me that document, databases, file systems, etc. generally acquire detritus over the years and over many software versions, and starting fresh can clean it all out. I haven't seen any specific reports about LR catalogs to that end, but...
One trick: select 1 image in a catalog with all the presets and other items you want. Export as Catalog. Then on the other catalog, use an Import as Catalog. Everything should transfer over and you can delete the one image you Exported/Imported if you wish. Also, Store Presets with Catalog preference is recommended.
One answer might be to create a new catalog,
Copy and paste the Presets folder from your Master catalog to the new catalog.
Identity Plates and Watermarks will be missing along with some other items, but you now have the basics of a 'copy' catalog.
If you watch this video you will get many suggestions for creating a "Template" catalog, if you ignore the references to "remote laptop".
Search the page for "How to use Lightroom 5 on Location"
select 1 image in a catalog with all the presets and other items you want. Export as Catalog.
Export As Catalog will transfer smart-collection definitions, but it doesn't transfer publish services.
create a new catalog, Copy and paste the Presets folder from your Master catalog to the new catalog.
To clarify, that's only required if the Preferences > Presets > Store Presets With This Catalog is checked.
Then make a copy of last year's catalogue and remove all photos from it.
Update: Do this while the computer isn't online, just in case removing photos from the catalogue triggers something in the published service.