I have 5 as well - 2 Adults & 3 kids..

I have 1 wash everyday and don't sort the colours - everything goes in together.

Friday night when DH gets home I wash his shirts on their own and then every 2 weeks I do the sheets and towels - I do DD and the twins beds every second Wednesday (they fit in 1 was) the towels every second Thursday and our bed every second Friday.

I also fold as I take things off the line and put them away immediately so I don't have clothes piles invading the bedroom.