LN is preferable only when you regularly make transaction. For example, default LN channel duration is 2 weeks so LN is preferable if you make more than 2 transactions/2 weeks.
Lightning channels do not expire. You are probably referring to a relative timelock of the commitment transaction. If the other peer is honest, you can come back online after a few months and you still will be able to use your channel. If you suspect that the other party might cheat, you just need to open your wallet slightly more frequently than every 2 weeks. A penalty transaction will be broadcast if your wallet detects a fraud attempt.
Yes, i actually refer to timelock. It's been a while since i use LN, so i have to ask how common that channel remain opened after passing it's timelock?
Also, the default CSV timelock is 144 blocks for regular nodes and 2016 blocks for mobile wallets.
Noted.