bunny9:
Nearest connection should be on the unit.
You mean there is WiFi internet connection available in each place you want to place a sensor? If so, I would recommend Wemos Mini. The difficulty with the Wemos, and with all esp8266-based boards, is that achieving low power consumption is not easy, and that will be required for solar/battery sensors.
How large a battery (in mAh) and solar panel (in W) will each sensor have? How many hours of sunlight is the panel likely to get in winter? How often will the sensors need to update the database? If the Wemos needs to monitor the reed switch at all times, the lowest power consumption I have managed to achieve with them is around 20mA. They have a very low power deep sleep mode, but cannot monitor inputs on this mode.
The anemometer and rain sensors in my weather station use reed switches. To achieve low power, I had to use a second, low power processor chip to monitor the reed switches while the Wemos was in deep sleep.
The advantage of LoRa is that sensors can be very low power and the signal has a very long range (up to 10Km with line-of-sight). But you need to have a gateway receiver and there are not many of those around except in certain cities, so you would probably need to buy or make one.