Saving on energy with new frames

House loses a lot of heat through the upstairs windows, and the bedrooms feel chilly on windy nights. Triple-pane keeps coming up, but the cost difference is big and I don’t want to waste money if double-pane with the right coating is enough. Also unsure about casement versus single-hung for airflow and sealing. Looking for a supplier that can guide me on the options and handle delivery to a small driveway. Any tips from people who already did this?