Wherever you cross the mountains, be sure to give lots of clearance for the wind coming over the ridges. Earlier in the mornings are better. If the winds are reported at more than 15 or 20 over the ridges I stay very far away... From Mammoth you'd probably be coming up the East side, so give them lots of berth, maybe 10 miles, and make the cut over right around Minden. Watch out for gliders.
But the nice thing is that KTVL is almost always 18 for landing, so just get yourself over the lake, then descend down and straight in. The airport is in a pretty clear area at the South tip of the lake, and you can see it for miles from across the lake.
Also, be aware that with the shelter at home order, Mammoth in particular is really not welcoming right now. "We're asking anyone who is not a primary resident of Mammoth Lakes or providing essential services to our residents NOT to visit Mammoth Lakes for the time being.":
https://www.visitmammoth.com/covid-resources
South Lake Tahoe is "encouraging visitors who are considering vacationing there to put those plans on hold":
https://www.cityofslt.us/1075/COVID-19
South Lake Tahoe has $1000 fines in place for people the rent short-term rentals (AirBnB) (both the owner and renter.)
Best of luck with your planned trip. I've flown over Tahoe quite a few times, landed at KTVL & Truckee, and it is strikingly beautiful every time.