Hi Emma. Sorry for your frustration. Please don't beat yourself up, though. You are doing an amazing job and it must be so hard if you're a working mother. Fortunately I'm a SAHM so I can work around my boys routines. Hats off to all you working mums
Ok, looking at how your day went, she had an a.m. catnap, a long sleep in the middle of the day (excellent) and then another late catnap. Had she not had a cold do you think she might have stayed awake for these catnaps? Of course as you say, everything goes out the window when they get sick! If she was well, I probably would have fought long and hard to keep her awake during the trip home (food, songs, loud toys, etc) and just gone for broke and put her down as soon as you were physically able after dinner, bath, etc. That afternoon catnap seems to be the culprit for mucking everything up!
Given she had that 10 mins in the stroller and a later wake-up in the morning (I'm assuming no NWs but I realise she had a later bedtime) I probably also would have stretched her out a little past 11.30 for her big nap. I realise this goes against what I've previously said about giving her the one sleep earlier and then progressively making it later, but she did sneak that catnap in and you have to make the routine work for you in the afternoon on working days when you have the commute home. So a wake-up at 7.20 a.m. and a bedtime roughly 12 hours later would have been really feasible, without that nasty p.m. catnap thrown into the melting pot! So if you can keep her awake on the trip home, I'd say she probably would have gone down quite easily at a bedtime as early as you could manage. Make sense?
My suggestion would have been to leave W2S too. I have absolutely no experience with W2S but the thought scares me a little
Maybe someone with experience in this area can advise you on this.
HTH!