Well, I guess I am going to put myself in your shoes.
I would do it, only if I could get in enough swims to get my endurance back up before the tri.
Additionally, I would probably want to get an ocean swim in before the tri as well.
Even having been a competitve swimmer and with the swim being my strongest event, I know that I lose my endurance if I haven't swam in awhile, and I am scared of swimming in the ocean.
I have a sprint tri in September, and because of my bike wreck, and needing to let my shoulder stop hurting... I won't be able to swim until about a month out, and that is making me nervous.
But, keep in mind, all of that is just me. I'm also the gal who won't do a tri because I refuse to walk the run portion.
I am sure you could make it through the swim... you might not be the "freshest"... but if you are OK with that... then why not go do it?
As we all know... a huge portion of this sport is mental... and you have to mentally be "in it" to be successful. Which means you need to start thinking you can do that swim.
Good luck deciding!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"