Don't know if its the sort of thing you are after but they have chalets for rent at Camping Isarhorn round near Mittenwald - about 15 mins drive from Garmisch - and very handy for the Lidl in Krun
In reply to chris59: stayed here twice in the past, lovely people, strongly recommend. If you do stay, Just let them know I say hi, and hope to be over soon (the Cookes)