You will not be far off hull speed
with both engines running in still air. You'll get good range on one engine for steady cruising in calms.
You'll just have to motor
sail into the right place and learn to drop sails
, or roller reef the genoa
and run in with the main until you can turn upwind to drop the main. How much you reef before the run in will be part of that.
Certainly my 34ft on 25 to 30 hp struggles to make good against wind
and tide under motor
as I found out when the roller wouldn't reef and I had to turn down wind to drop the sail and stow it. By that time I was a mile or so down wind and tide against a choppy swell. One of two times I wished I'd had a mono with a good engine. The other is manoeuvring but then you have two props, makes it SO easy.