On another thread, we were discussing the Pendragon game and one of its interesting features (besides its mechanics for personality traits): its concept of a Winter Phase. Knights adventure and quest throughout the Spring, Summer, and Fall, but in Winter they return to their castles for an "off season".

What would make for a good Winter Phase in D&D?

In Pendragon, the Winter Phase comprises nine steps:
  1. Perform Solo -- Participate in a solo scenario, maybe administering your own estate, serving your lord in some manner (escorting someone, border patrol, etc.), starting (or continuing) a romance, challenging all who pass a particular bridge (for "love of battle"), etc.
  2. Experience Check Rolls -- Characters improve between adventures.
  3. Aging -- Pendragon campaigns don't squeeze dozens of adventures into a year or two.
  4. Check Economic Circumstances -- Pay cost of living and collect income.
  5. Stable Rolls -- Horses age and injure themselves, and they're very important to a knight.
  6. Family Rolls -- There are rules for marriage, children, and family events (births, deaths, marriages, scandals).
  7. Training and Practice -- Players can direct some of their characters' progress.
  8. Compute Glory
  9. Add Glory Bonus Points

Some of those steps are very game-mechanic-specific (Experience Check Rolls, Training and Practice, Compute Glory, and Add Glory Bonus Points) and would probably get rolled up into one D&D step: Level Up. Others would carry over quite easily: Perform Solo, Aging, Stable Rolls, and Family Rolls. Either they'd use the same rules (Stable Rolls and Family Rolls), or they'd use D&D equivalents (Aging). The solo scenarios are obviously quite open ended. Checking Economic Circumstances might take some work, but you can start with the Upkeeps rules.

So, what do your heroes do in their off time now, and what could they be doing? What solo scenarios do you recommend?