First:
I assume you have at least one prepaid SIM card. Otherwise it should neither be hard nor expensive to buy one. You can buy one at every gas station even in other countries than mine, i assume.
Then: Register this SIM. This is usually possible by cellphone. Often there are offers like "Buy our 5gb (or something) data-plan and get 3gigs free of charge." I'd be on the lookout for stuff like this in these situations.
Buy a "big" data plan and just put enough credit on this card to pay for it.
Another possible solution is to have some pre-registered SIM's laying around. Especially when you are travelling a lot, i'd recommend this approach. Put some credit onto each one of these if you can't get an estimate on the best LTE connection you might get at locations you'd expect to travel to.
Then you can test.
Then:
Option 1: You trust WLAN. This is the easy one. Setup a hotspot and use your tools like you use them at home only this time on a laptop.
Option 2: You don't trust WLAN. Then you'll need a long USB micro to Standard cable to connect your devices. But "poof" online again.
I don't recommend using public hotspots because with certain devices even sitting down there will grab unsolicited and unwanted attention.
I also don't recommend using the jackpoint of a friend or something like this.
You're drawing even more attention when you're not changing your MAC regularly (which is not possible in every configuration or if you gotta administrate stuff).
First thing you gotta turn off (obviously) are youtube autoplay and manjaro updates.
But then you can use these SIMs till they burn out. Or rather you decide the'll fade from your life.
there doesn't seem to be anything here