With Hermione reduced to stammering, Ron just shrugged and repeated his news for Harry's benefit, "I might have a lead on the Horcruxes."
It felt odd just saying it like that, given that the situation was so much more complicated. Hermione was actually speechless, and he was already regretting leading with that bit of information, even if it was both the key development and his best shot at convincing Harry and Hermione that working with a double-agent was worth the risk. But he felt guilty, too. Hermione was so excited that she was almost speechless, which he couldn't remember seeing before.
Turning to Harry, he added, "Look maybe we should go inside, though, yeah? There's a lot I have to tell you both, better do it inside where it's warmer."