Choose a hotel with an indoor pool if the weather is too cool for swimming. If sports are popular and you live in an area where it is possible, attend an event together. Cultural events are popular, too. Make certain your grandchild will be interested in, say the opera, before you go there, however. Interactive science museums are normally still a hit at this age.
Crafts still have an interest, too.
It is a good age to teach a child to sew, knit, or crochet if they seem interested and do not know how. Try to bring some school lessons to life by visiting a working farm, a historical place, a museum. Children this age would still like to hear about their roots. Maybe an album set up with old ancestors with stories that can be told and related back to the child would be good. Don't feel hurt if the child wants to take along a friend at this age.