Just finished the rest of the challenge (did Asia earlier in November, now Americas and Europe):

Day One: DL LAX-SFO (no problem here, miles already posted) & SFO-MEX redeye (United positioning) - The SFO-MEX on AM was much higher priced than United so took a chance on this one although was worried about the MEX transfer from T1 to T2 (for an AM flight to JFK). Immigration/customs was surprisingly smooth but took a bit of time to find the AeroTren from T1 to T2 (located halfway down a long ... corridor and then across from T1 through a dark corridor - as others have mentioned (i think in the MEX transfer page) that you need your onward BP or some proof of your next flight to take the AeroTren).

Day Two: AM MEX-JFK (8:55AM departure...ended up using one of the priority pass lounges which was much better than sitting in the terminal - massive confusion over which gate the plane took off from so had to switch gates 3-4 times (quite a long walk between the different areas). An ominous sign on the departure board was every single flight was delayed - looked outside and the tarmac is completely fogged in. Uh oh....anyways around 2 hours later the fog started to burn off and we took off 2 hours late. Starting running through JFK to realize that at 4PM incoming flights were relatively light so breezed through immigration then our VS JFK-LHR took off on time. Storm Darragh gave us a nice boost and got to LHR in 5.5 hours overnight with a bit of turbulence when landing.

Day Three: AF LHR-CDG / CDG - MAD (3 hour delay leaving LHR due to cancelled planes from the Storm, AF cancelled our originally ~1:30PM flight out of CDG to MAD and put us on the 8:55PM plane). Lots of time in the "Blush" Lounge in LHR (nice brownies) then we were off to CDG for the long layover with a planned jaunt into Paris to take a photo at the Eiffel Tower and dinner. Alas, the Uber pickup was a complete mess and we couldn't find our driver and didn't fancy the train ride, so used our Euro 26 vouchers from the delay. Not much to do in CDG in T2E (as we needed to leave T2F and cross the road) to get to the Schengen Terminal. Ran into the aforementioned Korean guy with the "SAS Challenge" LED bag from previous posts (btw message me, I forgot to get your contact) who happened to follow us on the next few flights. Made it to Madrid and finally overnighted after two straight nights on the planes.

Day Four: UX MAD-FCO / RO FCO-OTP / Wizz Air positioning (OTP-CPH) - Things went relatively to plan on this day compared to the last day although Air Europa was using a super old plane and the AC or something had leaked onto the seat next to me (we ended up cleaning it and the guy who sat there then proceeded to elbow me out of my own space!). Tarom flight had comfy seats but seemed like they were using a plane from the 1970s. OTP - absolutely nothing to do here, so the downstairs area is much quieter for transfer and lots of seats compared to upstairs. Wasn't going to pay 45 euro to enter the only lounge in this terminal. Wizz Air flight was interesting as i've never seen a flight with so many drunk people walking around talking and changing seats. Got to CPH at 9:00PM so even faster (Wizz Air was the most on-time flight on my entire trip!).

Day Five: SK CPH-ARN. We are finally done. We go to talk to the SAS staff to make sure our FF #s are on the BP (as the printed BP doesn't show the SAS EBB #). The staff looked at us dumbfounded and were asking us "what number do you guys want"? Had to show them a screencap of the Million Mile Challenge.....multiple ones had never heard of it. Yet they agreed to take a celebratory picture with us for the last leg and were still astonished their own company is offering this promotion and wondered if we are being "catfished" or "SASfished".

That ends the trip. Awaiting VS, UX, and RO credit. Great to read many success stories from wizened vets and newbies. Key takeaways here - your flights are bound to get delayed in the winter in Europe and US...so build in time! Make sure you bring extra slippers on the plane cuz my feet were definitely not feeling "swell" after nearly 60+ hours in Y flights and transiting airports so good to remove your shoes. Use your status or Priority Pass, etc. to get into lounges as it's much better than sitting outside on hard seats. Most of all enjoy the process and have fun - something will go wrong, but "usually' it will work out just fine