There's no limit to which you can go in that case, which doesn't sound like a long term solution to me...But.. What do i know.
You can use hardware/internet growth when deciding block size increase, BIP 103 (
https://github.com/bitcoin/bips/blob/master/bip-0103.mediawiki) mention such scenario.
But this idea bring many question/problem with no universal correct answer/solution :
1. What hardware should be used as reference? Raspberry Pi? Newest Intel/AMD processor?
2. Upper limit of the hardware costs used as reference
3. Should we use slowest/average internet growth as reference
4. What if block size growth is too big to the point HDD I/O speed can't keep up and SSD the only option, which makes storage costs growing quickly (e.g. Ethereum blockchain size which is about 3.8TB and grow about 1.6TB in last year)
What Hardware do you think LN hubs will be using?
Why do people want to exclude that hardware for bitcoin but include it for LN?
Ethereum blockchain is based on a trying to be a smart contract system with millions of different coins on it.
Don't try and be a programming language instead of a blockchain and the insane bloat they have won't follow.
Considering Litecoin has an equivalent blocksize 4X bitcoin size in a 10 minute period.
Moving bitcoin to an 8MB block is still less than litecoin and you don't hear litecoin node operators whining like little girls.
Sad day when bitcoin community is too scared to even come near litecoin transactions performance, let alone exceed it.