Save it. It’s good to have a few boxes of your exact lot # Incase you need to replace any areas down the road.

Save it for the inevitable. Life happens and when it does it will require repair/replacement of parts of the floor. In less than 2 years, you will NEVER be able to find your vinyl floor. And just as Murphy's Law predicts, your life event will occur within WEEKS of the last box being sold in your country. And that will be that. You will need a WHOLE new floor or...you have to harvest flooring from your spare room and then have to find something to fix the spare room.

Either way, you will have wished you had saved the extra boxes.