Here is my Celestron 14" Edge on the CGE PRO mounted on my backyard pier with the Tempest fans getting it acclimated for the night's session. I have a ridged dew shield but also have a closed cell foam extension that I made and slip onto the ridged shield (not sbown). That gives me around 30" of dew shield total. I need every bit of it too with night time humidity that is easily in the mid 80% but sometimes gets all the way up to100% as the night progresses.
That's a very nice setup you've got. I have wanted a C-14 for years, but could not see myself lifting the 45 lb. weight of the optical tube. Having a permanent pier like you have, even without a slide-off roof, must make setup easier. I have my C-11 on a similar pier. Here on the Oregon coast the humidity is also quite high, though the temperatures are mild. The last time I observed (a few nights ago) the temperature was around 50° with a 45° dew point. After around 3 hours the temperature dropped to 45° and fog formed (100% relative humidity). So while we have different observing conditions, the effect with moisture is similar.
I would suggest the use of a DewBuster controller along with two heater strips to control moisture. Your Reflectex covering could also be employed over the dew heaters. While it is not inexpensive the Dewbuster is made with industrial quality. When fog ended my observing session mentioned above, the air was quite thick with moisture and dew covered most exposed surfaces. Yet there was no dew on the corrector plate. So the Dewbuster is quite effective and uses the least possible battery power. I believe Kendrick makes a similar dew heater controller.
The photo shows my C-11 with an AT115EDT triplet APO on top. I usually run two dew heater strips right below the corrector cell. That is the best location for the heaters according to the information of the Dewbuster website. It is much less effective to heat the corrector lens cell like on some heated dew shields. The corrector is well insulated from its cell by cork spacers and air gap.
The DewBuster website has a wealth of useful information about dew control. Ron Keating (the proprietor) knows what he's talking about when it comes to dew problems. Following the instructions he gave I made a dew heater for my Telrad finder. It is powered by one of the medium power outputs on the Dewbuster. I found the commercial dew shields for the Telrad to be useless. But with the home made heater the Telrad window never dews up, even though it is openly exposed to the moist air.