How exactly does loot respawn work?

[Gimli]

I have it set to every two months and 300 hours unseen. I want loot to respawn eventually but I also want it to take so long that it forces me to move around and make bases in other towns. I'm not entirely sure how far away the player character has to be from an area for the respawns to start taking effect.

[martindirt]

Loot respawn is useless in solo games...
1: 2 months is just not enough to use up initial loot in 1 town
2: if you reloot the same town again and again, you will end up with tooooo much shts in your base, you will never use
2b: tooooo much shts in your base impact performance badly. You will encounter lag after the game have to load up all your looted stuffs as you get close to your home.
3: you will die / get bored after maximum 1-6 loot respawn. (Or before the first)
For new players, loot is abundant enough for their lifetime.
Experienced players (imo) looking for ways to make our lives harder, make loot rarer.

For me this means:
10 years later
Home modded loot rarity (bit rarer than Xtreme rare)
Home made better zombie loot (rare, but more variable. I can find any item from vanilla / mods on zeds. Killing zeds is rewardable)

Back to your original question.
I'm never played SP with loot respawn, but afaik it's enough to be few tiles away from the container to enable respawn. Imo, it's enough if you don't see the container inventory.