I've been solo mining BTC for over 5 years and it is always good to have lower latency to your bitcoin node, however what is more important would be the number of connections your node has up and downstream.

Make sure you open up the listening ports to enable more nodes to connect to your mining node to have faster updates in terms of mempool tx and especially new blocks being found to ensure you don't mine a stale block.

In terms of "chances" of finding a block just because you have a local node, it wouldn't matter for nuts as it is all pure random chance as that is what sha256d mining is right now and there is NO benefit to having a node locally compared to one that issues getblocktemplate jobs from half way round the world.

It is similar to the myth that some shops gives you a better chance to win a lottery just because a few winners were from there in the past. Statistically, the myth is perpetuated because as more people buy from a particular shop it has a higher chance of finding a lottery winner. As more "foolhardy" people queue to buy from the shop the chances of lottery winners from that shop increases just because there are more people/combinations.

If you have multiple blocks in a day, yes invest heavily in low latency setup and have nodes running in the same subnet, but if you are thinking of doing it for fun/luck, best to invest in getting more miners @ the lowest price & electrical cost.