Check airbnb, vrbo, craigslist, or if you're looking at a vacation hotspot, local realtors often do monthly vacation rentals. Monthly rentals are often much cheaper on a per-day basis than weekly rentals. Your SF rent is going to go extremely far just about anywhere else. I am renting a 2br vacation house on the beach for less than the price of studio.
VRBO caps the platform fee at $500, but on airbnb it's uncapped. I messaged several listings directly to see if they would offer a discount for a longer stay, and several said they would.