The secret to warm feet in Portland is 1) keeping your socks dry and 2) keeping wind and water off your ankles.
For 1) I use shoes a size lager this time of year. Then I put my bare foot in a produce bag. The usual socks. Another produce bag. A thin, stretchy high sock that old men wear. Tights go over al this.
For 2) I made Portland gaiters from stretchy outdoor fabric. They are about 7" high. Width of the top half is for a snug fit around my ankles under my tights. Bottom half to go over my cycling boots. (I now use them also for by cycling shoes but that had not occurred to me when I made them to fit over my 45 North Fasterkatt boots. There is leakage between the gaiters and my shoes but they still help a lot.)
Now, those boots, if the work for your feet and cleat/pedals, are the cat's meow for Portland. Rated to and good to 25F (says this cold blooded guy old enough that he no longer generates the heat he used to ). They are for SPD/2-bolt cleats. They are great riding, good walking and comfortable indoors. Also fast on and off once broken in a little.
Ben