Yes you can. Rene Pickhardt demonstrate how he sent 1 BTC over LN . Here is his YT channel with more demo videos https://www.youtube.com/user/renepickhardt/videos

Over LN you can literally stream payments. The only restriction is the size of the channels on the path. If you can find enough liquidity, you can send 1 BTC easily.

https://bitcoinmagazine.com/technical/pickhardt-payments-how-to-send-large-bitcoin-payments-on-lightning.

My personal biggest payment over LN was 5M sats, using 2 hops. But for example you could very easily send 5 payments of 1M each over the same route. Why smaller amounts is better? because sometimes the routes are limiting the max HTLC to avoid fast drainage of the channels.

I am not worried about the limitations imposed by nodes, but by people not using LN and opening big channels. I still see people opening tiny shity channels of 100ks sats, with public nodes ! Maybe for a private mobile node is OK a 100k sats channel, but for a public one, must be bigger than 3M-5M sats at least.

Imagine a pipeline struggling to send large volume of water through tiny pipes....

Very good question btw.

I'm not the right person to ask. @DarthCoin be able to help you. I think if the channels have sufficient liquidity, it's possible. For those amounts, though, I'd probably use the mainnet.