Connection distance

I have had 50-60 feet in the same house (wood frame construction). But since both are on WiFi, that can be further. However, if you are on a phone call, and exceed Bluetooth range, the call may drop.

Unlikely you are going to have WiFi coverage over that wide an area.

While cellular towers are everywhere, the question is do they give you coverage in the wooded area you will be roaming over. If you do have good cellular coverage, then a cellular Apple Watch might work. But if you zero bars, or just a weak single bar on your iPhone, the smaller radio antenna on the Apple Watch is less likely to pick up the signal. And if it barely picks up the signal, the Apple Watch will be cranking up the radio power to stay connected, which will eat the battery faster. You may have noticed it cannot have a very big battery either.