We will be spending a few days in Copenhagen with a 80+ yr old family friend, and are trying to think of activities for him. He walks unassisted, but prefers shorter walks so bus trips and boat trips would be his preference. What would you recommend? Also which of the museums or castles require less walking? And how much time should we plan for if we decide on Tivoly Garden. I assume there would be plenty of benches or places to rest for the older guests.
A boat trip around the habour and canals would be ideal, depending on the weather of course. Go for the Nettobådene, they are much cheaper, but nice. There are also hop on-hop off busses if thats your thing.
From my memory, most museums require a bit of walking, though this is not something I think about when i visit them, so I can't say for sure. The National Museum is very nice and free, but I don't recall that many benches on my last visit. You could visit Ny Carlsberg Glyptotek (or just Glyptoteket, free on tuesdays). If you friend needs a break he can have coffee and cakes in the café in the Winter Garden there http://www.glyptoteket.com/visit/cafe, in fact I would visit just for the café.
Tivoli has lots of benches and nice restaurants as well. How much time depends on how many rides you want to go on. The park itself is fairly small, so if you don't want to try any rides, it can be seen in a couple of hours.