How Can Macbooks Be Connected to Portable Displays?

An iPad with Apple Sidecar. If you already own an iPad it's an obvious choice. It's easy and wireless (except requires charging). It's also extremely light and space-efficient.

Cons:

• If you don't already own an ipad it's a relatively expensive solution.
• It's small unless you go with the 13 inch Pro but if you can spend $1100 on a 13 inch travel monitor you probably can afford to have your advance team set up your workstation before your arrive :)
• It requires that both devices be signed in to iCloud. Fine if you already do that, maybe unacceptable if you've chosen not to.