I have no issues washing my king size down comforter in the W1. Two king size down/feather pillows also not an issue.

Adding to what Cal said about washing a king-sized down comforter in a W1 model, you can watch this video of a king-sized down comforter being washed in a Miele: https://www.youtube.com/watch?v=EGA0k0Z56FM

But, you asked about a quilt. Did you mean a down comforter or were you asking about the kind of quilt that is stuffed with cotton, wool or polyester batting?

IME, the batting materials in quilts are much less compressible than down. Down comforters/duvets deflate considerably when soaked. Batting materials don't. The deflation of down allows even king sized comforters to tumble and get cleaned in 2.3 cut. drums as in the Miele W1 models. Assuming you can even shove a batting-stuffed king-sized quilt into a compact washer drum, the quilt is likely too dense and too large to wash evenly in a compact washer.

Might fit in a Speed Queen FL model. Best to take the quilt to a display model somewhere and be sure that your quilt fits loosely enough to tumble and get cleaned. On the lack of a heater, that might or might not be a problem if you can place the SQ near the water heater. Depends on how hot you want the wash water to get. Did your readings turn up Jeffrey Caban's thread on how his FL SQ took in hot water (from a water set at 140°F) and how it was able to maintain relatively hot temps during wash cycles? If haven't seen that thread yet, the [Link is here.[(https://www.houzz.com/discussions/my-three-weeks-and-counting-with-a-speed-queen-fl-afne9bsp113tw01-dsvw-vd~5193795)

FWIW, you might not be limited to the unitized Speed Queen stack. Although SQ discontinued production of the separate (tho stack-able) FL models, some dealers seem to still have a few of the home FL models on hand. For example, I learned last week that a dealer in the city nearest me has one on the floor and two more in the warehouse.

When you mentioned Electrolux as an alternative, you were referring to full sized models like the EFLS527/627 rather than the compact EFLS210, right?

We are a family of 9. I had a Miele 4842 series washing machine for 7? years. I could wash a king size quilt in it. When the water inlet valve(s) started to cause me trouble, we looked into fixing the machine, and decided it was less expensive to buy a new machine. :( I still miss it. I do like how much larger the new machine is, though. I don't have any experience with the W1 Miele machine.

I went to an appliance store during a Costco run. They didn't have a Miele on display, however they did have a Bosch. I am very concerned about the capacity. I also asked about. the Little Giants, it sounds like they are the same smaller capacity as the regular machines.

jwvideo - Yes, we have a traditional quilt with cotton batting. I did come across Jeffrey Cabans thread, I think I will re-read it again tonight. Our laundry room is far enough away that I'm not sure about how hot the wash water would be, I'm going to ask my hubby how much more we can turn up the hot water heater. I've done some calling around and finally found one 45 minutes away. They are supposed to be calling me back tomorrow with prices.

A washer with an internal heater eliminates the need to turn up the hot water heater which is a very bad idea with children in the house.

I'll second the recommendation to skip the Speed Queen FL and look at full size washers with on-board water heaters like the Electrolux you mentioned in your original post.

There certainly are ways to protect the kids and others from the risk of scalding water at the taps by adding mixing valves and some other re-plumbing. But would you find the time, expense and hassle worth it when "Our laundry room is far enough away that I'm not sure about how hot the wash water would be?"