I think that's perfectly fine. Besides, you can upgrade the M2 drive to 2 TB; It shouldn't cost much.

For your lightning node you'll also need a bitcoin core node. The blockchain is currently about 500GB un-pruned and without the transaction index. I'm not sure whether LND needs the transaction index. I know core lightning doesn't need it, but Eclair does. Even with 1 TB you'd still have enough room.