You must acknowledge that the "youngest" of the Columbia 36's are over 35 years old. Therefore the overall sea worthiness of any of them depends on how they've been maintained. There's not much on mine that hasn't been replaced, repaired or painted. Some things more than once.
The Crealock design is very sea kindly in open water and many of them have been solid passage makers when properly equipped. They were, however, designed primarily as a coastal cruiser/ CCA racer ( PHRF 156).
The Large coach roof ports tend to "craze" with age and sun exposure. I've replaced all the ports with opening ports for ventilation. Some folks switch to mid boom sheeting on the main to open up access in the aft cockpit.
There's no getting around the basic value of a solid hull 36' boat albeit with 60's and 70's technology for the prices at which they can be had.
Expect however to invest in refrigeration, diesel repower, standing and running rigging
, painting topsides and hull, re upholstery and canvas.
If your base boat is less than 20K, with some sweat equity you can have a sound vessel that, properly fitted and crewed can go anywhere.