LMP - why not go with my suggestion as for where Eodwine could find Wilheard? Personally, I don't see Wilheard as a slacker (he's more like, mischevious and a little disinterested normally? and now depressed) and not a late riser by any means, I think being a morning person/ someone who sleeps very little anyway would better fit his character. I did not want ask you to rewrite your whole post, so I rather decided to go a different route to justify this ooc behaviour from Wilheard. I think this might be fun! But please, next time, ask me first, even if I'm seemingly not around -
Legate is more diligent than I am and he keeps me updated on Scarburg.
So, basically, I'm thinking he went riding at night, got his clothes wet, caught a cold and has a rising fever now, high enough to make him a little confused. It makes sense Eodwine didn't notice it at first, especially if he expected Wilheard to be slacking and his perception was coloured by that.
But if we want, Wilheard could also have brought a disease from Edoras (if it's one with a long incubation period) or maybe from somewhere else in the surroundings - I mean, for the past few days, he's been a lot on his own, riding around, so maybe he met say travelling traders and got something from them. Or anything. The possibilities are as many as we want them to be...