Consider having an on site auction with an auction company. Everything disappears in 1 day. Then you just have to move the money. When you get to the new house, start accumulating stuff all over. You would want to pick out your most cherished possessions to exclude and move.
I had an auction once from an auction house. They came and got all the stuff and hauled it to their place, where they had regular weekly auctions. It was easy. Some stuff went too cheap, some stuff went for stupid money, it all worked out on average.