Re: 1 USB port? Seriously?
When people need access to legacy hardware, they usually use an adapter. This is how it worked when floppy drives were removed from laptops, when CD drives were removed, when serial ports were removed etc.
There are variety of ways to handle your particular case -- and I say this, because I have exactly the same use case myself.
In the case of sensors, it turns out that writing to the SD card consumes more power, than sending it over WiFi or Bluetooth. But, if you don't have the infrastructure, that's different limitation.