If you have lots of bubble wrap lying around perhaps due to doing a lot of online shopping, hence you get lots of parcel deliveries, you should consider using them for your windows. I read about it in one of Alan’s newsletters and then did a web search to see how to apply it. It was really easy. I only used a spray of water + tea tree oil to put the bubble wrap on my windows. I didn’t really have a lot of bubble wrap but I just wanted to experiment so you will see I’ve only got half the pane done which is perfect for you to see the difference as your view will be obstructed but not light.
Bubble wrap double glazing