In my story of landing at MCO in November: we landed on time at 5:10pm. Our flight had a load of wheelechairs and SW got them off first, so the disembarking seemed to take forever, but probably was a 15 minute wait on aircraft. We were then at Level 1 Concourse B, checking in with Disney and in line for Art of Animation at 5:35pm. We were first in line, which thrilled my kids, but I knew we had just missed the bus. That WDW roller they play on the TV screen gets old pretty quickly. People stacked in around us.
According to my notes, we then waited until 6:15pm for the bus to arrive. We then sat on the bus and waited while I could hear other guests arguing with the bus driver about bags. The bus filled. We finally were off and at AoA by 7pm. It was a hair shy of 2 hours from landing to Resort.
So if applied to your timeline, you'd basically get to the resort around 8pm. Reservations for 8:45pm would work, but any slow downs would really press into that time and you'd still be on Magical Express feeling pretty stressed about it, starting your vacation feeling crummy.