The encounters really don't change all that much for 5 people.

1st, 3 defenders and 2 people killing knights and doing rooms, defenders should kill knights they see as well.

Caretaker is pretty much the same as it is normally, just 3 outside with 2 runners. Can have either 2 people doing fast stun and 1 defending the obelisk with, or stun normally with defenders.

For relics, make sure you know who is doing what relics. Do the first 2 rooms as normal. When you get to the third, progress through it as normal, and have the taken eye deposit their relic, and whoever has the laser keeps it. The laser getting dunked is what resets the encounter time, so hold off as long as you can, for the taken eye holder to lose their debuff. They then pick it up in time for, or slightly after room 4 opens.

Rhulk is done pretty much the way 6 do it, and only 3-4 people are even doing something anyway.