I’m working on a spherical dungeon. It contains many monster factions that are bound to anchors so they cannot leave their areas. As the players destroy the anchors and beat the factions the strength of the other anchors all increase leading to the factions having access to each other’s spaces. The deeper the faction’s anchor is beneath the surface the more they benefit from the expansion of their range.
I do this. I learnt it from a game called Torchbearer which features a travel subsystem. The journey gives you a toll based on how far it is, what sort of terrain etc. To pay a point of toll you need to expend a ration of food and one of water, else you can pay it by having equipment break such as shoes and armour or you take horrible conditions.
You can take a role on the journey which increases your individual toll but allows you to do something that will benefit the whole team. A scout gets a chance to save against encounters. A hunter or forager will test to find food. A cartographer will map progress. A cook tests to stretch those rations. A guide is essential to get to the destination.
A difficult journey has resulted in the party sacrificing their animals which is something I’d never seen happen in any other system!