That's a great question rdy-b.
Unfortunately, as warm as its been (mid-forties in January is 'exceptionally' warm for us, plenty warm for northern bees to fly around) its not warm enough for me to risk going that deep inside.
However, the bees I see at the inner cover hole licking up the sugar and those flying about sure look like young bees, even the bees I find dead in the snow 'appear' to be young bees, w/ lots of fur, fat, golden and with perfect little wings :). I've brought several back to life already this year just by holding them in my hand for a few minutes.
Based on what I've read and observed in the past brood rearing has very likely begun again, and I'd think with the increased temps they're perhaps fooled into thinking the season is further along than it actually is and maybe the queen is laying MORE than she should BEEEE. I don't know. Lots of questions this winter that's for sure :-\