You'd be amazed at how small a space people can put a true longarm in. I visited a new friend last week. She had a 12' A1 in the back bedroom of her single wide manufactured home. They had taken the doors off the closet, and part of the machine was in the closet. To get to the back of her machine, she had about a foot at one end to squeeze thru. Luckily, she's a teenie tiny thing. I'd have to take off the batting roll rod, and stop, drop, and roll to get from front to back! I have no idea how they got it in there, I would have guessed it to be impossible, but they did it!!
The dealer that sold my A1 to me said that 75%-80% of the machines she sells are to people who are not going into business, they are doing their own quilts.