A total of 1 review of this product on Reddit.
Following up re: temperature. You could look for an oil-filled radiator that you plug into the wall. From my research this is the safest heater for birds. Many electric heaters actually contain PTFE which is the chemical in Teflon that is toxic to birds when overheated (it can kill them), so you do not want just any heater. The oil-filled ones do not contain this chemical though they may have other chemicals on them from the manufacturing process which burn off after a few uses. If you purchase a new one, I would recommend running it out in a garage or far away from the birds the first week to burn off any chemical from manufacturing. Then it will be fine. I have found them pre-owned on Facebook marketplace or Craigslist for very reasonable prices (like $25-$45). They are also very easy on your electric bill, much more efficient than other heaters. Something like this oil filled heater
There is also a cool little heating device you can put directly into the cage, but being that you have 2 birds, you may want to get 2 so there is not fighting over it. It’s called K&H PET PRODUCTS Snuggle-Up Bird Warmer on Amazon, it’s currently $39 but I got mine for $35 so maybe price will drop again. bird cage heater
And lastly some people use heating pads laid over the top of the cage, you just want to make sure there’s nothing unsafe that they can reach and nibble on, something like this heating pad