Do you think that Weezle would do the job? I’m also considering tecline.
This is bit like the question, "How long is a piece of string"? It depends.
No matter *what* you wear in 35F water it will keep you warm for a finite period of time. You will lose heat and get cold, eventually. The only questions are how long will take and how much your body temperature can drop safely.
If you plan short-ish recreational dives and start them when you are warm, the Weezle Extreme might suffice depending on dry suit type, activity level, and your metabolism.
On the other hand, if you plan 2-hour exposures with a significant deco obligation (which carries a low activity level so you don't generate as much heat), you will need an electrically heated vest or undergarment and an additional undergarment. All this bulk will mean a larger suit. If you compress the primary undergarment it will not keep you very warm.
The suit material will also make a difference. A "Unisuit" style 7mm neoprene suit is warmer than a compressed neoprene suit, which is in turn warmer than a trilam suite.
A *good* cold-water hood or a dry hood is essential. You lose a lot of heat through your head. Likewise you will need dry gloves with warm liners.
Technique will likewise come into play. The need to keep enough air in the suit to let the insulation work requires that you pay attention to it and you might need to carry more weight than you do now. IIRC, water weighs about 64lbs/cu ft. You don't have to displace much more to need to re-weight by a few pounds.
A rebreather will keep you warmer than open circuit, too. Warm air vs. cold air makes a difference.
I've probably forgotten something. Hope this helps.
