I want to move my node to a laptop with less than 70gb free space. Would pruning make wallets older than pruned blocks unusable? If that is not an issue, what files should I copy to my new node in order to keep using my wallets?
Once the wallet has already scanned a range of blocks, you can safely prune these blocks. However you won't be able to re-scan this block range in the future.
Copying your wallet file over to your fresh node should be fine as long as the wallet's tip (the latest height at which it was synced, ie opened on the old node) is superior to the last pruned height on the new node.