In reply to MikeR:
>Can you recommend any particular hut tours close to Bavaria for a 4 or 5 year old?
Not hut to hut as all my stuff so far has been day trips. In Bavaria itself there doesn't appear to be much because the mountains tend to be small ranges with roads between thus there's only one hut in a range, or you have big ascents / distances too far for kids. I've not really looked at the area east of Mittenwald though as that's not so easy to get to for me. I suspect there will be some good info on the DAV site - I'm sure there's pamphlets or books of 'kinder huttentours' available. Alternatively, googling 'kinder huttentour' would appear to give you some decent results.
From experience, look at the Kolbensattelhutte / Purschlinghaus - Kolbensattel has a playground and a summer rodelbahn down from it, but I don't know if you can stay there. If you can't, it's not too far to the Purschlinghaus. Also, the Hoernle hutte - it too has a chairlift up to it to skip the boring track through the woods from Bad Kohlgrub, then you can take in the 3 Hoernle summits & Stierkopf close by in a kind of loop and stay in the hut. You could also maybe take the cablecar up toward the Alpspitze then over the rinderscharte to the hollental hutte, stay there, then descend through the klamm the next day (adults can do it in one day). There's various things for kids to play on in the woods below the klamm. The Brauneck meadow area above Lenggries is good for kids - we just did a day loop from the top cablecar station up to Latchenkopf and back via the Stie Alm, but there's a hut 'over the back' by the look of things. There were cows and paragliders for the kids to see, and a small summit east of the Stie alm to scramble up in addition to the main summits.