Yes you can or on a tablet or another device. The easiest way is to use the same Google account on the devices. This makes sharing easier.Can you plot goole map routes on a PC and then download them?
Google maps can create a unique link for the journeys you have planned. Way points can be added to force a specific route or add a stop on route. You can then share the planned route or save the link it creates.
I often plan our next day's route whilst away on my tablet as it has a 10 inch screen. I then 'share' the route to Google Keep Notes. I can then open Keep Notes on my phone (which I use to attach to the Uconnect head unit via Android Auto Auto) and click the link.