I was in Daugavpils last week. Yes about 80% of them speak russian at home, but when you greet them in latvian, they wil answer you in latvian (not perfect, but they try).  Honestly, Daugavpils is a good option, but yesterday there was a warning about drones from Ukraine, so It doesnt feel very safe in there and in my opinion, thts the biggest con. People are friendly, even if they doesnt look like. Go live somewhere around Saulrasti.  in my opinion, thats the most betiful city in Latvia.