should i upgrade from my e90?

currently got a 2011 328i n52 with 148k mi on it. it’s got an issue where it won’t heat no matter what, coming from a potentially chronic water pump issue. replaced water pump, thermostat, coolant temp sensor, heater core flush, radiator, and expansion tank. no heat when not idle and constant water pump reduced power code. trans also slips from 2-3 and 3-4 on occasion.

this 2018 430i b46 came up near me for $15k with full msport and everything with 80k mi. i really love my e90 and don’t want to part ways but i live in a place where it’s below freezing for over half the year so its just extremely not viable. should i keep my e90 and get the f32 also? sell e90? try to fix it more?