I use SkyRoam's original hotspot. Uses a proprietary technology to connect to cellular data networks in a huge number of countries around the world, and then makes a hotspot to which you can connect five devices. It costs US $8 per 24 hours of continuous use, including in multiple countries you might visit during those 24 hours. Activate a day pass only on 24-hour periods when you are away from free/hotel/lounge WiFi access. In addition to the built-in $8 day passes, you can insert a local SIM so that you can save some money if you are staying in one country for many days.
(I do not work for SkyRoam and have no connection to the company other than being a satisfied customer.)