Just wow!

My personal advise. Get your self a lot of small containers like from IKEA or just throw away take away food boxes. Start with small batches. Do large parts first. Sort by category, part and then at last if needed by color. I do this regularly on my boys collection and we are able to even build 1000+ pieces sets again and again. We have like 15 Ikea samla boxes (multiple for bricks, 3 for plates, vehicle parts, large parts, transparent parts, multiple boxes to sortminifigs and equipment and so on) and for really tiny parts extra little boxes like 1x1 plates. One for white black and grey and another for colors. I don't see an other way of stay sane even on small collections with just 10k+ pieces...