Luke, I live/hike in New England. Lots of rain, but mostly stay on trail, so most of the time, but not always, less vegetation to wet legs & feet. However, we get a lot of rain. I used an inexpensive pair of LLBean GTX light hikers (32oz per pair in my size) when I first started to lighten up. My feet sweat a lot. Now, I use NB 805’s (still have a couple of pairs in reserve that I got at 70% off – couldn’t resist).
Since you appear to be intent on keeping your feet dry, apparently for good reason as you state, you might try:
To keep my feet dry (from outside moisture), I use Integral Designs VB socks. Easy to put on if rain starts. However, these don’t breathe and hence sweat builds up inside them. Since your feet don’t sweat much, you might try them. You can try them either over or under your socks – but I keep at least a thin Smartwool liner between them and my feet. You might also try a GTX sock (e.g. Rocky Roads, IIRC – try Campmor.com), or a Serius Storm sock perhaps (?? I know nothing about them). Of course the shoes still get wet, but they dry quicker than if water got into a pair of boots!! Hope this info helps.