You sound organised to me.
Don't know if this helps anyone, but just in case, here's what I've got. Choices will not be for everyone, as I lean towards Hilton/IHG (I get free perks from them), considering location compared with stadium (public transport options) and obviously price/comfort (I don't do anything worse than a Premier Inn). Based on who is still in the competition, I have cancellable reservations at;
Munich; 11/12 Premier Inn Munich City Schwabing (or Hilton Munich Park), 18/19 Premier Inn Muncih Airport Sud
Madrid; 11/12 & 18/19 Indigo Madrid Princesa
Naples; 11/12 & 18/19 Holiday Inn Naples
Milan; 11/12 Doubletree by Hilton, 18/19 Doubletree by Hilton Milan Malpensa
Porto; 11/12 Se Catedral Hotel Porto, Tapestry by Hilton, 18/19 Arts Hotel Porto, Tapestry by Hilton (or Porto Palacio)
Lisbon; 11/12 & 18/19 Hotel Acores Lisboa
London; 11/12 & 18/19 Doubletree Chelsea. London still has plenty of reasonable priced options if willing to use tube/bus to get to Stamford Bridge
Already cancelled; Frankfurt, Paris, Dortmund & Brugge :D
If you're OK making cancellable reservations, I would suggest you do so for Munich & Milan, as one, or both, potential dates have some crazy pricing for accommodation, that will only get worse once the draw is made.