Should I stick with my current RAM (2x8GB DDR4 2667mts) for my new PC build?

In a couple of months I’m planning to build a new PC with an i5‑14600K and an RTX 5070. I already have the 5070 since I found it on Amazon for £520, which seemed like a solid price.

Because RAM prices are pretty high right now, my plan is to reuse my current RAM (2×8GB DDR4 2666 MT/s) and go with a DDR4 motherboard for the time being. I know this RAM is on the slower side, but I’m planning to upgrade to DDR5 and a new DDR5 motherboard in about 1–2 years, even if RAM prices don’t drop much.

I have a few questions:

1. Does this seem like a good plan for now?
2. How much performance would I actually be losing at 1080p compared to running 32GB DDR5 6000MHz?
3. Does anyone have any other suggestions or a better approach?