We've been potty training for 3 months now, and dd is dry at home - she goes 2 or 3 hours between trips to the loo, and although she rarely asks to go is happy enough to perform when we put her on the loo.
Nursery is a different story - she is in the preschoolers room 3 days a week and regularly comes home with 2 or 3 bags of wet clothes.
Would I be unreasonable to ask them to be a bit more proactive about putting her on the potty every couple of hours? She's 2.5.