45,000 satoshis... even if it was just a simple "1 input/1 output" transaction, would be around 200 bytes... even at a "low" fee of around 100 sats/byte, you'd need to use a fee of 20,000 satoshis, which would mean you could only send 25,000 satoshis.
Electrum is telling me the lowest I should use is 136 sats/byte which would make the fee around 30,000 satoshis. If you get "insufficient funds" at any number, it means that the fees that Electrum is calculating, is larger than 45,000 satoshis... so you transaction must have several inputs.
Anyway, in Electrum go to "Tools" -> "Preferences" and on the "Fees" tab, check the box that says "Edit Fees Manually"... when you go to send, you will be able to specify whatever fee you want... so you can try sending with a 10000 satoshi fee or something. Just realise, that if your fee is too low, it will take a LONG time to get confirmed (possibly days) or could even be totally ignored forever by the miners.
yep. that's now often less than the average bitcoin fee. you could try moving the private keys to a wallet with complete control over the fees and try a lower fee.
Have you actually used Electrum? It is one of the few wallets that DOES give you complete control over fees, to the point where you can switch off all the fee estimation stuff and just type in the actual fee amount manually. 
