mm thickness for farmer john style wetsuit

I need a new wetsuit.
I fish mtn. lakes in all seasons.  Water temps down to 38F, but usu in 40's.
I have a worn out 3 mm,  but was thinking thicker.

7 mm too restrictive?
3 mm was fine for me, including surf landing practice for 3 hrs. at Half Moon Bay in spring long ago.  I might fish salt water in BC, Canada, but I'm predator-leary in N. Calif. 

I avoid getting in the water, have never dumped, but I fish very rough water at times and in rain (occ waves splash across bow - Pyramid Lk NV, Tahoe, etc.).

How thick?

Thanks for you thoughts and reasoning.
- Tom

7mm is too restrictive for paddling.   I used to wear 3mm before switching to drysuit and never going back.

I was looking for a thicker than 3mm neoprene farmers John myself. Couldn’t find any at the time. Decided to get a neoprene top (also from NRS) which I like very much since I can take it off if I’m too hot.
But feet were still cold. Especially when wading for too long waiting for the sets. I ended up getting dry pants to go over the wetsuit. It works very well. The only thing I haven’t tested is how much water the pants would get if I’m immersed (since the pants aren’t combined with a dry jacket). But so far this hasn’t been an issue. Plus, I usually take off the dry pants after launching.

I was looking for a thicker than 3mm neoprene farmers John myself. Couldn’t find any at the time. Decided to get a neoprene top (also from NRS) which I like very much since I can take it off if I’m too hot.
But feet were still cold. Especially when wading for too long waiting for the sets. I ended up getting dry pants to go over the wetsuit. It works very well. The only thing I haven’t tested is how much water the pants would get if I’m immersed (since the pants aren’t combined with a dry jacket). But so far this hasn’t been an issue. Plus, I usually take off the dry pants after launching.

I use neoprene socks on colder days with my neoprene boots. I prefer the shorty socks. easier to take off .

I have a 4/3 Farmer Jon, works well for me. Can bundle with jackets/pants of chilly out, and isn't too hot until it's over about 65 put, which is about the point when I just go in shorts or synthetic material pants anyway.

For feet, I have 7mm booties for when it's cold, and 3mm neoprene socks under Crocs/sandals in medium temps, and then just bare feet above about 60 or so.

When I first started I wore 7mm farmer john which I used to wear for ab diving. It was 2 piece wet suit, farmer john and top. Even without the top it felt restrictive so I got a 3mm nrs farmer john.

3/4 or 3/4/5 with titanium lining seems to work well. Decent flexibility and the liner retains heat. 1mm boot socks also w titanium. Use wind breaker and splash pants to beat wind chill.

I used a 7mm suit before when we dove for abs as well as fished from yak. I found it that thickness to be constricting and uncomfortable for time on the kayak. YMMV

7mm is too restrictive for paddling.   I used to wear 3mm before switching to drysuit and never going back.

Completely agree, angler drysuits are pricey but keep you warm and dry with the right layering.

Got dunked at doran when the nws updated the scw ( big wind once I was out) in a 3mm.
At the beach 30'out, I was 1 cold azz mfer.
Can't think of a thicker being flexible,  so warm or comfy?
I don't know...

My concern is getting dumped and having to spend some time in the water before getting myself back in the kayak.  I don't want to get so cold that I get physically impaired.  I used to practice dumping and re-entry, but it has been a few years.  Getting older, like over 7 decades old, I am not as nimble or strong and have some realistic caution about not responding correctly/quickly/efficiently like I did in my younger age.

I suspected that 7mm would be too restrictive for paddling, and so I guess it is time to bite the bullet and go for a dry suit. 
   Thanks for all of your suggestions, comments, and ideas.  Points are well-taken.
- Tom

You won't regret the decision about buying a drysuit.   It worths every pennies.