What an acre will hold can very widely depending on where, climate, what sort of ground. You also have to consider what livestock you want to carry over winter, and whether they'll be housed or not. They'll need forage (hay, silage) - shall you make it yourself or buy it in? If the former, you'll need ground on which to grow it.
I don't know where you are now, but 2 acres doesn't sound much for 3 horses

May be ok in spring/summer, when the grass is growing and it's not too wet underfoot..
The 'normal' rule of thumb is an acre per horse or cow, 5 sheep to the acre. Double the ground - at least - if it's wet/rushy. And double again if you want to make your own winter forage.
Having said all of which, for the livestock and uses that you list, more than 10 acres could be a burden, less than 3 could be very very tight.
Spare acres can usually be rented to local farmers / sheepkeepers, so it would be better to have more rather than less, then there's room for expansion.
