I think you've identified the problem correctly, the screen height of zero
affecting a broken pager. Normally rancid sets the TERM to "network" in
rancid.conf, which implies a height of 0. AND, clogin sends the command
'term length 0' to disable the pager. Assuming your device does not
recognize the 'term length' command, try setting TERM to something which
normally has a fixed height, such as vt100.

Another possibility is to use hlogin, which has become somewhat the home
of the bastard children, with the addition of a stty command to hard-code
the height to something greater than 0. Note that hlogin also tries to
disable the pager with HP's 'no page' command.