I actually did this just yesterday. I purchased an 8.4” VP4 Nav unit off of eBay for around $300. Bezels can be expensive (+/- $150) but it is simple plug and play, same connections as smaller unit. I switched because my original unit died. It took me less than 20 minutes to swap units. You will need a 911 override cable (911 Vehicle Phone Override Cable – Infotainment).
I thought about an aftermarket unit but you need functionality of your climate control so I never pursued it.