I don't have any other physical machines that I could give ssh key access as backup..
There must be a web-based personal terminal provider that you can set up on a permanent basis? Then you could access it from anywhere, even when out with mobile etc. But I'm not sure which to go with/trust.
Or do most people just have a cheap secondary laptop?
If you want a mobile kit for hotel room without carrying laptop there you can try some HDMI screen mirroring dongle (Google Cast).
If you wanted, you could run https://github.com/huashengdun/webssh on the sever you are trying to access, or something equivalent to a Boston server. This is something you should definitely host with TLS, and some form of authentication.
You could use something like this: https://github.com/PHPAuth/PHPAuth You could also use Okta.
NodeJs for the server which spawns a process to execute bash commands.
I assume there is something like that for iOS, or other phones.