Does airflow work this way between rooms?
I could not recommend your strategy.  This is not how we comfortable warm a room. You may need to break your single loop into two loops or even three loops. Almost never would we connect an entire house on a single loop.  The first radiator would be too hot and the last would be too cold.
The heaters that are in each room should heat that room or the heater is not sized properly or the piping connecting it to the boiler is not sized and or designed properly.  P.