How does your smart schedule look like?

I'm trying to find the most comfortable and yet efficient heating scheme for my not so well insulated bedroom.

I set a temp for the bedroom at 18C for the night and the boiler turns itself on and off many times. I've read that it's not very efficient as it takes around 10 minutes for a boiler to reach max efficiency.

I created a smart schedule that every 2 hours it heats up the room up to 20C and then lets it cool. So on average temp is about 18C. But it doesn't account for the weather and cooling speed - it can drop to 16C during cooldown on a cold night which is too cold. Or it can only go down to 18C on a warm night.

My question is - is there a way to set up a hysteresis for on/off operations? Or use some additional logic (IFTTT?) like "if temp is 17C -> heat up to 19C and switch off"?

What is your setup?