With my 20 footer, same as Op has, when I would get grounded I would jump out and pull it off myself, also had two anchors for such use, would do a Roy Rogers and toss it ahead, then pull boat ahead, and do it again.
When I had the twin Johnnies, came back home on one motor more than once, no insurance, didn't need it.
Don't see what else is at issue on twins? Disabled physically, fine then.
If you loose both engines on a twin, you deserve to be hit with big bill.
When I had the single, the longest distance breakdown could occurr - occurred, when OMC POS 20 buck ignition sw shorted out, cost me $350 tow.
Didn't happen again for all these years, so it's a risk assessment, cost me more looking back to have the insurance so I dropped it on twins, the money banked for 10 yrs will now pay for anything once, and then some. Each additional year I'm making out more not having insurance on the twins. I can't loose. If it happens once, I'm still ahead, but will get the insurance for then on.
So not having insurance now pays me 10 bucks a month for doing nothing, no membership required. I like that.
Hail Coast Guard and they will get you in touch with commercial tower, if there is none to come, Coast Guard will come, it's their job to begin with.