I recently traveled and I brought my old iphone 6 and made sure my physical SIM was compatible with both and checked with my carrier as well. One issue I keep running into is that the digital boarding pass and email communications for updates from the airline just make issues like flight delays, reroutes, lost baggage, or missed flights so much faster to deal with, especially if there are minute by minute updates and a time crunch in an airport I’m not familiar with. I guess the best answer there is to have a dedicated email address for airline comms and make that the only connected account for your backup smartphone.

Qwant off of Orion on iOS. Don’t bother with Kagi. There are better options if they switch to graphene.

EDIT: SearXNG is perfect in every way except for consistently returning useful search results.