Most important aspect of GPU for Resolve

Hi,
I use Resolve 16 with my BMPCC4k footage. Currently my GPU is a 1070ti and it will regularly give me the "GPU memory full" message when I try to use TNR and other GPU effects. Presumably this is meaning the 8gb VRAM is maxing out.
With the new 3000 series cards approaching from Nvidia, it would be interesting to get peoples takes on which will be best for 4k video editing (without spending a fortune) i.e. is the 3070 plenty seeing as it more than doubles my current CUDA core count while maintaining 8gb VRAM? or should I get at least the 3080 with 10gb VRAM.
Here are the specs for the new cards.
3090:
CUDA cores: 10,496
VRAM: 24 GB GDDR6X
Memory interface: 384-bit
3080:
CUDA Cores: 8,704
VRAM: 10GB GDDR6X
Memory Interface: 320-bit
3070:
CUDA cores: 5,888
Memory: 8GB GDDR6
Memory interface: 256-bit
My current graphics card is as follows:
1070ti:
CUDA cores: 2,432
Memory: 8GB GDDR5
Memory interface: 256-bit
I use Resolve 16 with my BMPCC4k footage. Currently my GPU is a 1070ti and it will regularly give me the "GPU memory full" message when I try to use TNR and other GPU effects. Presumably this is meaning the 8gb VRAM is maxing out.
With the new 3000 series cards approaching from Nvidia, it would be interesting to get peoples takes on which will be best for 4k video editing (without spending a fortune) i.e. is the 3070 plenty seeing as it more than doubles my current CUDA core count while maintaining 8gb VRAM? or should I get at least the 3080 with 10gb VRAM.
Here are the specs for the new cards.
3090:
CUDA cores: 10,496
VRAM: 24 GB GDDR6X
Memory interface: 384-bit
3080:
CUDA Cores: 8,704
VRAM: 10GB GDDR6X
Memory Interface: 320-bit
3070:
CUDA cores: 5,888
Memory: 8GB GDDR6
Memory interface: 256-bit
My current graphics card is as follows:
1070ti:
CUDA cores: 2,432
Memory: 8GB GDDR5
Memory interface: 256-bit