The advantage of a small body of water, whether it's a lake by itself, or a bay or a channel is that it will really challenge your tacking skills.
Not long after I got my DS, I once spent an enjoyable hour late one summer night tacking up a deserted shipping channel where the wind blew only along one side. We had to make each tack as close to the side as possible and not lose speed on the windless side. (At that point in the day, or rather night, not using the motor had become a point of honor).
However, anything below 300 acres will probably feel limiting. I've sailed a smaller boat than a DS on a lake with about 250 acres and despite an island to provide something to sail around, it didn't offer enough interest for me to seek it out again. However, I regularly sail a different lake around twice that size with my DS. (There's a speed limit, so powerboats are not a problem, but better get out of the way of the occasional gravel barge
) Without using the "exits" on either end, the lake is good
for a leisurely 2h daysail.
Altogether, the nicest situation is where you have connecting bodies of water, or a larger lake with a convoluted outline. Then you get to explore different sailing areas.