@ SkyWatch ... separate the solar sensor from the rest of the sensors. ...
I did that with a TP2700WC, and lashed the solar sensor + rad-shield near everything except the temp/r.h. sensor, which is in the xmtr pkg (downside, probably should buy another shield (such as from AmbientWeather, for a WS1080, which is similar, to protect xmtr from the 'elements'). If you use extension cable (I've forgotten whether 6 conductor was necessary), be sure any connector(s) doN't crossover pins. In other words, check continuity to be sure that what will plug into the xmtr corresponds to plug pinout with the original cables.
An advantage of extension cables is that sensors can all be in relatively auspicious places for each of them, and distance from xmtr to baseStn can be minimized.
Some issues:
1) power from the solar sensor may not be enough to keep the xmtr batteries charged on a series of lo-Sol days
2) Alkaline batteries in xmtr may not stand up well to deep cold. I use newer, 2450 mAh NiMh.
3) Random changes to time and/or date on baseStn may be due to RFI impairing WWVB reception
4) Another EMI/RFI issue is with the USB cable. I use a ballasted cable, routed *away* from backside of baseStn.
5) Solar sensor (and possibly power) may degrade over time
6) Rainfall may fail to reset on baseStn, at local midnight. Manual reset has been an ongoing pain after ~ 1st year.
If you have a poor location for siting a weather stn, being able to separate sensors may offset some of the issues noted. Otherwise, saving money on the stn is liable to cost extra effort...