SAS from Chi to Florence Premium Economy? How to book?

The SAS website does allow multi-city booking. At least it does on my iphone using Safari.

https://www.flysas.com/

At upper left on the booking page, where it says Roundtrip, touch the arrow and it will offer a drop-down menu choice: Round trip, one way, or Return from another Airport. Choose that one.

Return from another airport only allows for two flights, not that middle flight for the layover.

I see OP's point; the "return from another airport option" is open jaw, not
layover.

I think the first answer is to simply call them and see if an agent can book it for you
and if it comes out at the same price as Google Flights.

The second option might be to book the open jaw to Florence and back from
Copenhagen and find a way to get between the two. For the FLR-CPH flight,
I might be willing to fly economy since it's a short flight.

Since you are looking for a 2 day stopover (not layover), you probably have to
book this as 3 flights, since the ~max layover time that a connecting flight will
show is usually ~24 hours.

Note that SAS will be moving from Star Alliance to Skyteam in 2024. Not sure if
that will make things better or worse. I could see codeshares through Paris or
Amsterdam becoming an option, but who knows what price that would be at.

Of course, once the alliance changes, there could be schedule changes and
alterations. I do think that the alliance change involves $ infusion from Skyteam,
which may alleviate the bankruptcy concerns.

Just for reference, it's a 90 minute train from Roma Termini to Firenze SMN. If you
can get a similar fare flying into Fiumicino nonstop, the overall transit time is probably
about the same. The open jaw completion option noted above could also be Rome
to Copenhagen.

Be aware that there is not going to be premium economy (or even proper business class) on intra EU flights.

If I were you I would just fly direct from Chicago to whichever airport in Italy that has direct flights. There is no need to always land as close as possible to where you are intending to stay. Look at Milan or Rome, and then just take the train to Florence.

www.Skyscanner.com shows ITA Airway and British Airways have some of the fastest direct flights ( taking 9- 11 hours) and the best basic fares for Chicago to Florence next September. That’s not to say the SAS Premium Economy fares are not the least expensive for that route. However, SAS appears to pair roundtrip tickets with at least the outgoing or the return flight from Europe ( and sometimes both) saddled with multiple stops and taking 25 to 32 hours. This is often the case with the least expensive fares that are shown online. So, be sure you know how long it’s actually going to take to get to and from Italy before purchasing any tickets.

Kenko and WengenK, thank you. I don't see any direct flights from Chicago to Florence using Skyscanner, Google Flights or the British Air site. I believe Delta has direct flights to Florence certain times of year, but not when we're going. But we can definitely fly direct to Rome. Thanks for your help.