You can always still use your finger to do the walking, searching, scrolling and selection on the 17". Just remember to keep your eyes on the road!
Seriously, another hands-free option would be to skip use of your MS Phone Call capability, and if you have say an iPhone, use Siri to place the call. Assuming you have your phone pre-paired, when it begins to dial, it will assume control of your 8.0 Media Player "Phone" (aka Bluetooth) connection and you can talk and hear through your MS mic and speakers without touching anything. I personally HATE doing workarounds for basics like that in my Tesla, as IMHO I just shouldn't have to if Tesla were listening to its Customers, but it is an option for you to consider ...no different than how some Owners that don't trust Tesla Nav or Traffic Rerouting, choose to use another mapping app or Waze on their smartphone to workaround what they consider Tesla Infotainment deficiencies.