I'll settle for hazard at this point, because I don't think we'll ever agree on the size and mechanics.![]()

How about we start them at Medium and take a fresh look at the strangling vines?
Strangling Vines (Ex): Any creature that enters the space of a strangle vine must succeed at a DC10 Reflex save or be seized by its vines. If they succeed, they must check again every round they remain within the plant's space.
Seized creatures are entangled, cannot move out of the space they where standing in when the vines seized them, and take 1d4 damage (plus Strength bonus, if any) per round from being "strangled". Any creature in a strangle vine's grasp cannot speak or cast spells with verbal components, because the vines wrap round their head and neck and try forcing themselves down their victim's throat.
A seized creature can escape by succeeding at a DC14 Strength check or a DC14 Escape Artist check. They can also break free by killing the strangle vine or cutting the vines that hold them; the vines are AC13 and have 4 hit points (8 hp for Medium strangle vines, 12 hp for Large, 18 hp for Huge, 24 hp for Gargantuan and 30 hp for Colossal). Severing the vines does half the vines' hit points in damage to the main plant. The DCs are Strength-based and include a +4 racial bonus on the Strength and Escape Artist checks.
I think the biggest thing that doesn't sit doesn't feel right to me is the changing hp for the vines. If the point is that you are wrapped up by multiple vines, shouldn't you just get tangled again as you try to cut out? Or maybe even burst out with a Str check?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.