What is TV reception like in Upwey?

Generally OK but obviously some areas with poorer reception. The TV transmission / signal repeater towers are located further up in the hills around Ferny Creek and Mount Dandenong so if you are located in the higher elevated parts of Upwey or are facing north you'll probably get better reception.
My advice would be to get a proper antenna installed - there are heaps of service guys operating in the hills (says something about the reception!). Most will do a signal strength check and advise on proper antenna and possibly a signal amplifier.