sed -i -e '/<Console>/,/<\/Console>/ s|<node>[0-9a-z.]\{1,\}</node>|<node>newvalue</node>|g' YourFile
i assume value is between your tag and and only contain small letter, dot and digit (based on your sample and try). If extended, just add character missing in the class like [0-9a-z._-A-Z:]
and maybe sub-class [:space:]
if newvalue
is a variable content, dont forget to use double quote and escape character &
, \
and the separator of sed s
action (default is /
and |
in my code)