You have a few inches on me. I like my P-T's and capes long - most of them come mid-shin. Eliminates needing any rain gear for the lower legs. Usually, gaiters, even shorter ones, suffice just fine.
Yes, sometimes if the trail is overgrown, it catches. Have never ripped or torn a P-T yet. Many of the nicer ones have a means of tying up at least the rear of the P-T which helps alleviate the problem you're envisioning.
If you're real concerned, it should be a small matter to sew (and seam seal the threads) small velcro dots to the P-T to allow you to, what's the word???, "hem up" (sorry, senior moment) the P-T whenever you need to.
Off-trail, any P-T on anyone catches if the brush is thick.