If someone is owning a too heavy wallet to move it the worst that can happen is that the transactions get canceled after 14 days!

Transactions don't "get canceled". Once broadcasted, each node can do whatever they want with it. Some will drop it, and your own wallet may drop it (depending on it's default, Bitcoin Core for instance keeps it). But some nodes may keep your transaction forever, which means as long as all the inputs are valid, it can eventually get confirmed.
Bitcoin Core by default only keeps your transaction in its mempool for 336 hours (14 days) before kicking it out:
-mempoolexpiry=<n>
Do not keep transactions in the mempool longer than <n> hours (default:
336)
But I'm sure you already knew that.
The chance that you'll find a node with a custom -mempoolexpiry is very low. But that's a good thing actually, because the sooner your low-fee transaction gets evicted, the sooner you can use the inputs to create a better transaction.