DISCLAIMER: I ACCEPT NO LIABILITY/BLAME SHOULD ANYONE ACTUALLY TRY THIS.If you have time and patience... and don't mind waiting for the coins to arrive... then, you can always attempt an "el cheapo consolidation"™ transaction
Basically, you're going to send ALL your coins to your shiny new HD wallet, with a minimum transaction fee and pray that you can get your transaction accelerated using ViaBTC TX Accelerator
Step 1. Ignore everyone telling you to use "Dynamic Fees" and/or "Recommended Fees" as you're going to use a manually calculated fee... and a stupid low one at that.
Step 2. Work out how many UTXOs you actually have to consolidate. "listunspent" will probably help you if you're using Core/QT.
Step 3. Do some basic maths: (#Inputs * 148) + 44 = Your guess at a transaction size in bytes
Step 4. multiply the figure from Step 3 by 20. This is your fee (use 20 sats/byte just in case you have old uncompressed addresses in inputs that make them ~180 bytes instead of 148)
Step 5. Create transaction to send your total Balance to an address in Shiny new HD wallet. In Core/QT, set amount to send to the total balance and tick the "subtract fee from amount" and then input the fee calculated in Step 4.
Step 6. Send out your transaction, get the TXID
Step 7. Start submitting your TXID to the ViaBTC TX Accelerator every hour until you get "Acceleration Succeeded"
Step 8. Go make a cup of tea, read a book, browse forums while you wait for ViaBTC to mine a block
Step 9. Enjoy the big giant UTXO that is now in your shiny new HD wallet
PROS:
+ You end up with 1 big UTXO in your new wallet to start, no need to worry about bloated transactions for a while
+ It's cheap.
CONS:
- Has the potential to go horribly wrong if you miscalculate the transaction size and/or fee. If you fee ends up below 10 sats/byte you won't be able to accelerate it using ViaBTC and your transaction will be stuck for days
- Could take hours to get transaction accelerated
- Could take more hours for ViaBTC to mine a block
- All your coins are unavailable until the transaction confirms.
Honestly, I really don't recommend this method unless you're desperate/stupid/drunk...