Small. I can’t speak for all classes, but for example Calculus is capped at 35 and Physics, 42. Essentially honors colleges are trying to replicate what everyone gets at Cal Poly, small classes where labs and discussions aren’t taught by TAs.
The largest lecture hall on campus is The Silo in the B-School. It holds 205. My son had one class in there, an engineering class that nearly all engineers take.
The honors college at Oregon will be good. The Honors College at Orgon State was one of the best we came across. I expect U of O to be similar. Not all classes will qualify though. It’s something to look into.
Eugene is a great town, not dissimilar to SLO in temperament. The biggest differences will be weather and athletics.
She should visit. They are both great options. One will speak to her.
Congrats!