In Monster Hunter Rise, you can either go on quests or go on expeditions.
Expeditions are like a free roam mode in the series and there’s no time limit for it.
Here’s how you can leave an expedition in MH Rise.
How to leave an expedition
To leave an expedition properly, meaning you keep all of the items you collected, you have to go to the menu.
Press on the “+” button on the Nintendo Switch. You’ll see the menu pop up. Look for the second tab, and choose “Complete Quest”.
They’ll then ask you if you wish to leave the expedition. And that’s it. You get to keep the items you looted.