A good senior trek has three properties: a short daily distance, a bail-out point, and somewhere warm to sleep. Plenty of routes have all three.
The Poon Hill circuit in Nepal is the obvious first: four days, teahouses throughout, and a sunrise over Annapurna that justifies every step.
Closer to home, the Kuari Pass in Uttarakhand and the Dzongri trail in Sikkim are both walkable in five days with porters and a slow schedule.
Whatever you choose, spend the two months beforehand walking hills at home. The trek is not the training.
