Any advice from people with experience at Sequoia NP in May would be great.

I'm flying to LAX this Saturday to start a two-week road trip loop. The itinerary is as follows:

Arrive at LAX late morning (drive to Exeter)
Drive Generals Highway through Sequoia to Mariposa
Yosemite (one full day)
SF
SF
Carmel/Monterey
Carmel/Monterey
Cambria
SLO
Santa Barbara
Santa Barbara
Anaheim (Disney)
LA

I decided to be a real tourist and rent a convertible Mustang (or similar of course) for the trip. I've been watching the weather at Sequoia, and up until today, the outlook was sunny for Sunday. Well now they have changed it to possible snow at the higher elevations. Should I cancel my drive up Generals Highway? Should I just change my rental car and get some chains even though I won't be able to use them? Should I get rid of the convertible because the weather is still too chilly on the coast anyway? Should I just go as planned and hope for the best? I'm not staying a night in the park, just spending one day driving through.

Any quick advice would be greatly appreciated.

Thanks,
Andy