Transaction too large
This is referring to the transaction size in bytes, not Bitcoin.
You need to send the Bitcoin in smaller chunks to yourself, or sweep the dust, as they say. This is because a transaction is made up of unspent outputs (UTXO) and since you are sending a large amount, you will likely have many small UTXO from all of the tips you're trying to spend. This increases the size of the transaction in bytes.
Bitcoin core will return that error if the transaction weight is greater than
MAX_STANDARD_TX_WEIGHT, which as of
v0.16.3 is 400,000, which also happens to be the maximum size of 1 block.
What is tx weight?
Transaction weight is defined as Base transaction size * 3 + Total
transaction size (ie. the same method as calculating Block weight from
Base size and Total size).
Virtual transaction size is defined as Transaction weight / 4 (rounded
up to the next integer).
Base transaction size is the size of the transaction serialised with
the witness data stripped.
Total transaction size is the transaction size in bytes serialized as
described in BIP144, including base data and witness data. See BIP