If you have to recover 4 years of blockchain data, keep in mind that by default that data is stored on your computer's HDD and the total size would be around 300GB.
So you should consider at least pruning, but even better would be to find out which addresses have funds (https://bitcoin.stackexchange.com/questions/96529/bitcoin-cli-how-to-verify-balance) and then dump (i.e. show in order to save them somewhere else) the keys as @joniboini said.

The address coins' worth can be seen on any block explorer if you know the address.
And the private key you can import in simpler wallet either now, either sometime in the future.