A preliminary question: When you say you’ve removed things from LR and your hard-drive, are these backed up somewhere else, or do you really never need to see them, again?
An obvious question: Have you emptied your recycle-bin?
And another: have you checked to see that the images are actually deleted, if you used LR to do it, sometimes it doesn’t actually remove the files.
How many images did you remove? How big are the images in megabytes? How big is your hard-drive? Just to check if the amount of space used by the images you deleted is what is free, now, and there’s a massive amount of hidden datas to find. If you don’t know how many images, then open the most recent backup copy of your catalog, before you started cleaning, and see what it tells you. The backup catalogs should be in a backup folder under where your current catalog is stored, which you can see in your preferences.
Another thing to do on a trip is to get a little USB-attached drive, the kind that doesn’t use a separate power-supply, and make a copy of your images over on that so if you run out of space on your laptop you can move the images off,. Temporarily, and have an extra backup of everything even if you don’t move any images off the laptop, in case something is stolen or destroyed, somehow.
1TB My Passport drives from Western Digital are a hundred bucks. You can fit three of them in your pocket.
That’s what I have several of.