Central Chile in August - Any help?
 

First time traveling to Chile, in mid August. Arriving from Bolivia via Uyuni tour and need some help with the central Chile portion of the itinerary. Thoughts on this?

Wed 8/14 arrive in Santiago in evening from Atacama
Thur 8/15-16 - 2 days exploring Santiago
Sat 8/17 - Drive down to Vik Chile in Colchagua - wine tasting, horseback ride, eating/drinking, spa
Sun 8/18 - transfer to another hotel in Colchagua and visit 2-3 winderies and lunch (Montes, Montgras, Lapostolle, Clos Apalta, Viu Manent?)
Mon 8/19 - drive to Valpo via 3hr stop at Kingston Family Vineyard in Casablanca, arrive in Valpo around 4-5pm
Tue 8/20-21 - 2 days exploring Valparaiso
Thur 8/22 - in Valpo until 5pm, then drive to Santiago and catch 10pm flight to US

I realize this is winter in Chile so it wont be very warm but I am also hopeful it wont rain the entire time. Would you agree with this itinerary?
Any hotel recos in Colchagua, Santiago and Valpo? No need to be fancy like Vik..that's a 1 night splurge for us.
Would you return to Santiago the last night and spend the last day in Santiago before the flight?

Thanks so much