If you can SSH directly into both systems, then you don't need to print anything directly to the terminal. You can go:

  ssh system1 'cat payload' > temp
  cat temp | ssh system2 'cat > payload'

Or cut out the middleman, as long as getting two password prompts isn't too confusing:

  ssh system1 'cat payload' | ssh system2 'cat > payload'

I've found the base64/copy-paste trick useful when I can't do a conventional SSH. Usually this is when one of the machines is accessed via a serial console.

In that scenario, it can help to compress the data before base64-ing it:

  machine1$ cat payload | gzip | base64
  <output>
  machine2$ base64 -d | gzip -d > payload
  <paste output>