Geraniums are relatively easy to overwinter. Some people keep them inside all year round! There are several techniques that people use, including forcing them into dormancy or even hanging them upside down like herbs...but probably the most familiar and least scary way to do it is just treat them like houseplants with a cool sunny spot and not too much water. Don't be too alarmed if they drop lots of leaves when you first bring them inside, and cut them back a good bit when you do take them in.

Coleus are tricky indoors -- they tend to get rot or bugs. But it's always worth a shot!

I've never tried lantana indoors, but they're pretty tough plants overall. Give em sun and not too much water, and see what happens.

Have fun experimenting!

Coleus are very easy to grow indoors! Sometimes they are kept overwinter as cuttings in water but are probably easier to keep in a soilless potting mix after rooted from cuttings. I have kept coleus through the winter for a few years now and have not found bugs and rot to be a problem.

I have not kept lantana indoors but know that it's not uncommon. Lantana is often recommended as an indoor winter plant, so it can definitely be done.

What can I say -- you're nicer to your indoor coleus than I am! LOL!