If you have outside intake and exhaust, your heating bill will be very high. If you can exhaust into the other room, your lights may give you all the heat you need. But you may want outside exhaust capability for summer. Depends on how good the insulation is.
I’ve installed one of those little Cadet baseboard heaters in a house I had to sell. Home Depot online has many of them at different wattages, and you can get a really cheap thermostat that mounts right in the heater frame. I had to install it because rooms heated with portable heaters don’t count for house square footage. Mounted baseboard heaters do count!
I’m heating over 100 square feet of well-insulated space with just my lights, and they are 400 watts of COB LEDs! But then again, 40 F is a record low in San Diego coastal. Get a Cadet.