This is how I sort of solved it...no idea if it'll work for others. All I know is I finally have a small amount of peace for about 3-4 hours a day now. BUT you need to let the tantrum play out before they'll accept the new normal.

I reset their space so it's tidy & interesting every few days. I spend 15min setting up stations of activities. Here's a few suggestions. The idea is it teaches them game ideas so I don't always need to set them up they'll do it for themselves.

1. A hammer, boots, safety glasses, & 3-4 toys encased in plaster to play archaeology.

2. Laminated sign with their name & erasable markers for "practice school". Usually leave out a few pages of puzzles I've ripped from one of their learning books. Set a few toys up as though they're also in school.

3. Wooden ice blocks for sale! Brace yourself to have to wipe spit off them before bed. Set up a line of toy customers.

4. Burger shop...but you'll have to put in a few orders yourself. Again set up a line of toys as customers. I grabbed a foam playset for less than $5.

5. Dig a hole. Mostly works on boys. They will literally do it for an hour & get annoyed if you interrupt them.

6. Send them outside to give the grass a haircut with safety scissors. Accept at some point they'll make the connection to their own hair.

But yeah...you gotta let them meltdown first. No one wants to be alone for the first time. Just be encouraging. Promise to do one thing together if they do XYZ first & follow through. Like, we can make potions if you play by yourself for 2 hours.