Wear nappies so you won't have to sit down on the pot. Bring your bed downstairs so you'll have no reason for going up and down stairs.
Or you could, as you say, do some light squatting sessions to ease into it but where's the fun in that?!
I also find that eating a TON of food immediately after training helps a lot with DOMS. And I have also read some interesting research on very sore muscles having less insulin sensitivity, so for recovery from DOMS you might be better off focusing on protein and healthy fats (which would have the added benefit of reducing inflammation).
I also find it interesting to hear you mention that squatting may have hurt your cycling performance. Obviously you know your own body best but I have found in the past that squatting improved my cycling performance (I would be more geared more towards shorter distances as opposed to mountain biking so maybe that comes into it).