Like to duck walk it down? Really depends on the bike. Go put a measuring tape under your motorcycle, stand over it, put your feet down, and see how much room you need.
I don't like those two fold ramps because you're either off-center or you're going up/down smooth metal in the middle.
I like at least 3 ft wide in case I need to put my feet down, but I'm also 5 ft in the air, not 5" in the air, so I take extra precaution because I've got a long way down if I don't lol
Typically though I ride all the way and don't put my feet down until I get to the door and have to hit the brakes and manhandle the bike through the doorway. I turn the bike around inside the house so I can just ride out, and with momentum going down is way easier. I ride down my ramp in flip flops because it takes 2 seconds. If you're stuck duckwalking/backing it out you'll probably want that extra space under you.