Go to nodejs install directory, go into node_modules and move folder npm to different location. Go in the bin folder inside the new npm location and set it as your working directory. Run node npm-cli.js i -g npm@latest and it will update the install in the correct location. After install, delete the temporary npm folder and you're finished.
Try to connect to the service you're SSH'ing into and automatically accept the key, run echo y | plink -ssh root@REMOTE_IP_HERE "exit"