My suggestion would be to replace the thermostat as if it had no significant use it wouldn’t be there in the first place. You said without the thermostat the fans are overworked. Now, you are giving licence for that to happen. Fuel consumption will always be on the rise too as there isn’t a thermostat to ensure the optimum temperature is attained quickly
. I think it’s not wise to have to go through all this just to prevent your vehicle from heating up. Just replace the thermostat to have everything back to normal :)