Best/smallest WIFi module for use with nano 33 BLE Sense

I got a nano 33 and need to add wifi capability to it. (mistakenly thought that it supported wifi on the board). My requirements are that it be as small as possible easily integrates (software wise) with the Nano.
The arduino wifi shield is too big. I found one from Adafruit #2471 that looks like it may work
Any recommendations appreciated.

The ESP-01 variant of the ESP8266 is slightly smaller and you would load a suitable AT firmware or your own code on it to do the Wi-Fi stuff.
Another option might be to use an ESP32 module that also has Wi-Fi and BLE to replace the Nano altogether.

the Adafruit ATWINC1500 is much better than esp8266. it is used with the established Arduino WiFi101 library.

if you really want to use esp8266 then you can use my WiFiEspAT library. it is even very easy to switch between WiFi101 library and the WiFiEspAT library.

Can the library be used on other hardware Serial ports such as Serila2, Serial3 on a DUE or Mega for instance ?

yes. the Serial port is provided with WiFi.init and it can be a SoftwareSerial too or for example my Serial1 library for the I2c to Serial converter chip on the old Uno WiFi Dev Ed.

it works even on 500000 baud over hw serial

just my library is limited by limitations of the AT firmware (for example only 1 server) and the low quality of the 'new' AT 2 firmware. (most stable esp8266 AT firmware version is 1.7.x)

Thanks for the replies!!!
So either the Huzzah ESP8266 ($10usd) or the ATWINC1500 ($25usd) will work, Just have to use the appropriate libraries. From what I quickly gleaned from looking at the repos, the library functions seem to be almost the same. Libraries and calls to them could be nicely handled by ifdefs.

Any insight as to power output/realistic distance with either of these two modules?