I did run 2 on Tuesday and run 3 tonight and found them a lot easier on the treadmill with no hills and no snow! I felt really good at the end of today's session, caught my breath much more quickly after the second 3 min run and felt like I could easily keep going.
I'm going to do a Week 3 run again on Sunday morning outside(!) and then start Week 4 on the treadmill on Tuesday. I think I'll cope better running outside if I've already done a session on the treadmill. I admire all of you for doing the whole program outside, I'm just a wimp
Looking forward to the lighter nights too which will encourage me to do more sessions outside (hopefully!)