Keep the boxes, life, as we have found out in the last year or so, is very unpredictable, you say you will not sell, i said that about so many ranges and sets, such as W Britains Zulus, War of the Nile, Clash of Empire, K & C Pike & Musket, T Gunn French Foreign Legion and Aussie/Japanese range, but i got fed up of them and sold them, they are worth more in the box, whether or not you feel that is stupid it is true. Plus you may move, you say you will not but who knows for sure......
After you have thrown off this mortal coil - the guy who wrote no one cares is taking a massive leap into generalisation, someone will care, your family and/or friends, maybe not about the figures but about the funds it could raise, you would not burn money, so why get rid of the boxes. Plus if there is no one to leave them too, do as i know a few collectors have done in the UK, they have left them to a charity [some to military veteran charities], most charities are clued in now and be able to get an expert to look through them and sell them on.
The only reason i can think of to get rid of the boxes is having no room, which is understandable. Mine are all in the attic or the garage, just get some boxes, shops and supermarkets throw loads away, to store them in.
I have a large collection, insured for a six figure sum, the boxes do not take up to much room, just a bit of organising, i am a bit of geek when it comes to storing, they are store by range in different boxes, once a box is full and labelled what is in it the box it can be put under eves of the attic of the house or garage and forgotten.