Definitely you want to crank the amp to it's sweet spot (which is usually at blasting levels), and then use a Hot Plate to attenuate down to a moderate level. It won't sound as good as if you did it naturally (it doesn't account for speakers being pushed which is a big factor) but it's still exponentially better than using a 100w Mesa at low volumes. A Mesa should never have the master below 3 or 4, pure blasphemy
Or, you could sell the Mesa 2:100 and buy a Mesa 20/20 poweramp which is far more appropriate for home use (and still VERY loud, you could gig with it) and sounds great at low volumes - and have money leftover too. Although, the 2:100 does get the most out of the Recto preamp so maybe that wouldn't be the best idea