If you want the device to operate all the way down to 3.3V just ditch the regulator. Your battery at full charge is 4.7V and the NodeMCU is specified 3.3-5V so you've got a perfect match there. A battery will provide a steady DC voltage that would only fluctuate if your NodeMCU sporadically draws heavy current (which is highly unlikely). Plus, you made an excellent battery choice as the Li-Po performs well under heavy load. It has the lowest voltage drop under load out of all the lithium batteries. So all you need to worry about is the mAh rating of your battery. The NodeMCU shouldn't draw any more than 220mA. So so if your battery is rated at 220mAh that means it will power your NodeMCU for one hour. You'll have to look up the actual max current draw in the NodeMCU's datasheet. If you're concerned about voltage sag and want a bit of a cushion, you'd probably want the mAh rating of the battery to at least double the max current draw of the device. A 1000mAh battery can supply 1 whole amp of current for an hour so it would have no problem supplyingwill be yawning at 220mA for 4 1/2 hours. mAh rating is usually printed right on the battery. Refer to the NodeMCU's datasheet to find out it's max current draw then use this calculator to see how long your battery will power it for. No need for a regulator. Hope this helped.
https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-battery-life