You can run sshfs with the "reconnect" option. We use sshfs with PAM/automount to share server files for each workstation in our network. We use -o reconnect as parameter for sshfs, mostly because our users suspended their computers and on wake sshfs would not reconnect (or respond, or anything).
For example:
sshfs [email protected]:/home/mvaldez/REMOTE /home/mvaldez/RemoteDocs -o reconnect,idmap=user,password_stdin,dev,suid
sshfs [email protected]:/home/mvaldez/REMOTE /home/mvaldez/RemoteDocs -o reconnect,idmap=user,password_stdin,dev,suid
Just a note, if the remote computer is really down, sshfs may become unresponsive for a long time.