Maybe. Probably.

The most expensive thing you can do is heat all the air in your entire home to be comfortably warm. The cheapest thing you can do is make everything colder.

You’re in the middle with a hybrid solution - using secondary heating to heat up specific areas. Since both heating sources are electric, and electric heaters are practically 100% efficient, it really just comes down to how big the area you need to heat and how long it takes.

For example, if you have a 2 bedroom apartment and you’re using space heaters to heat both rooms and, say, the kitchen, what’s really left? The bathroom? You’ll probably have spend more money buying heaters than you’d ever save on energy.

On the flip side, if you run the main heat low but then every morning your bedroom is cold and you’re miserable for an hour while it heats up, is that really worth the ongoing misery to save not-very-much-money every morning?

If you don’t own any heaters yet, figure out what they’ll cost and what your heating actually costs you. If the savings are less than the energy savings over a couple of years, I wouldn’t even explore this any further. Dropping your thermostat a couple degrees and wearing a sweater inside will get you a lot of the way there.

Another thing you can look at is insulation efficiency. Is your place expensive to heat? That’s because your warm air is escaping. Why? Feel around floor seams, outlets, windows, etc for cold drafts - that’s cold air coming in and forcing you to heat it back up! Sometimes a hole in a wall can be trivially taped over to cut this down. Are the windows especially bad? Keep the curtains drawn. You can even buy plastic wrap kits that you basically stick over the whole window to trap the air. It works well but then you can’t use the window until you take it down in the spring.