I chrono a flying unit on a 1 vs 1 map, and it took the same time to cross the map than in a personnalized map with a playable size of 108*108 (128*136 overall size when you create the map). But I suppose all 1 vs 1 have not the same size assuming one of them is described as "big" (it's the one I took for my comparaison, so maybe an average is more like 100*100 -120*128- but my timing is not very precise).
I chrono a flying unit on a 1 vs 1 map, and it took the same time to cross the map than in a personnalized map with a playable size of 108*108 (128*136 overall size when you create the map). But I suppose all 1 vs 1 have not the same size assuming one of them is described as "big" (it's the one I took for my comparaison, so maybe an average is more like 100*100 -120*128- but my timing is not very precise).