If you are flying in for the Tasmania Cup, there is no need to hire a car.
Here are some accommodation options that are all within walking distance of Princes Wharf 1:
Harrington’s 102
https://harrington102hobart.com.au/
Prince of Wales Hotel
https://princeofwaleshotel.net.au/
Grand Chancellor Hobart
https://www.grandchancellorhotels.com/hotel-grand-chancellor-hobart
The Old Woolstore Apartment Hotel
https://www.oldwoolstore.com.au/
Vibe Hotel Hobart
https://vibehotels.com/book-accommodation/hobart/hotel-hobart/
Mövenpick Hotel Hobart
https://movenpick.accor.com/en/australia-pacific/australia/hobart/hotel-hobart.html
Travelodge Hotel Hobart
https://www.travelodge.com.au/book-accommodation/hobart/hotel-hobart/
Best Western Hobart
https://bestwesternhotelhobart.com.au/