I have been updating a number of laptops for myself and relatives recently. In the past, for laptops and desktops I use Freefilesynch to make frequent backups of data to one or more usb HD’s, and approx weekly Macrium Reflect images, also to usb HD’s. Newer laptops have micro or normal SD card slots and I have installed 128 gig ones and use them to backup files using windows backup via Settings. Data is typically only about 80 - 100 gig.
For my own laptop I am thinking of buying a 256gig Micro SD card ( about £30- £40) and using that not only for data but also for one or two Macrium images( about 70 gig each when compressed)
For travel it seems a good idea? I will continue with usb too. Any suggestions! Are these SD cards reliable? It seems a very reasonable solution