What no it wouldn't be impossible to collect things without the map a few people here on the forums have gotten all koroks and shrines without using a guide. Most people use the maps as a guide and reference point and most do so from the start. Easier to do it as you go along than it is to save...
Or alternatively collect everything as you go along so that you know the boundaries in game.
Though i gotta agree the ability to filter regions would be damn helpful. Did a 100% korok seed run all 900 of em and i did a regions seeds as i discovered that region. I'd have rather had all regions...