The foredeck option will be a challenge on a 27 footer, but worth exploring, except then where do the bikes go. I manage this at 32' but only have one bike and no wife to transport.
Towing may be only option. Tow line length is the key. But still even with two bikes in the dinghy (secured) I'd consider a watertight cover, if that's even possible, over two dighys to manage.
Don't buy expensive bikes.
I have towed offshore
one time, and my first time travelling offshore
six years ago. Line length right, everything hunky dory all day long. Swell on the beam. Then turned to go in south of Ancloe Key to anchor
so swell was astern and not big. But the little boat was swamped within fifteen minutes. With floatation, I towed it awash to the anchorage. Then put a couple of fenders under it to get the gunnels up, and bailed it out.
Maybe a tow line adjustment was in order, don't know. Haven't tried it since.