I have almost always had a get home alternative on board--many times that was sail...
In 1961, I had a V8 in a 26' Owen's Sea Skiff fail--I had fabricated an emergency bracket out of 2x4 "just in case", put that on the swim step, and used the 2H johnson dinghy motor to get the last few miles home from Catalina--slow but did the job.
I had a transmission fail, on our 62 foot sailboat--in the Rue d'Brest, with the tide just starting to ebb. This boat weighed over 65,000 lbs, and got her up to about 2.5 mph with a 4 hp dinghy motor on a 10' hard dinghy This gave me steerage way, and allowed time to inflate & launch the 13 foot inflatable, and getting the 25 hp outboard on it going--got the big boat up to a little over 5 mph. Breeze came up--and got some sail on--enough to stem the now ebbing tide of over 6 knots--and eased the boat into a side tie at the municipal marina in Brest...
I found that using an inflatable as a "tug" and pushing was the best way to handle this situation. By pushing a large boat, you use the motor in a directional fashion as a rudder. If side tied, there will be torque and side displacement before you can get the larger boat moving.
Had a few engine failures, but those two above, were the only ones where I had to use some kicker type of assist,--and could not immediately "fix" the issue (such as as a fuel problem.)