If you’ve manually selected the USB as your boot device in the BIOS and it still gives you that error, it sounds like your windows install USB might be borked. Do you have another PC that you can use to reflash it?

My first thought is to go into your power options and turn off “fast startup”

Step by step instructions

As long as the SSD is being installed into the same exact system, the easiest option here in my opinion would be to clone your internal SSD to the external SSD, then swap the larger external into the laptop. There are plenty of walkthroughs online about how to do this.

This article covers cloning a Windows 10 drive, but the same steps can be followed for a Windows 11 install as well.

What your friend is referring to sounds like either

1. A power line ethernet adapter. These work by sending data transmissions through your already existing electrical wiring so you don’t need to run additional dedicated network wiring.

For your specific use case (using it in a hotel) the power line adapter probably isn’t going to work. One of the main requirements of those types of adapters is having both adapters (you need 2: One for ethernet in, one for ethernet out) on the same electrical circuit. You can technically have them on separate circuits, but this seriously degrades performance and sometimes outright just won’t work at all.

2. Wi-Fi range extender

This type of adapter might work for you. However, if you’re having connection issues between your laptop and the wireless now, there’s little chance this will make any meaningful difference in your experience.