Sometimes the hardest part is simply showing up with a cohesive, acclimatized, uninjured team where no one is sick.
I’ve met expedition partners in “easier to get to” expedition locations, where there are likely to be other teams, for example the Kahiltna(and Talkeetna). I’ve heard of some great partnerships being forged in the Khumbu as well.
If classic mountaineering is your thing, you’re likely to meet people on the popular mountaineering peaks… Aconcagua, Denali, Pik Lenin, any 8000M peak.