Only rule is you can't spend more then 1/4 on one project, person or idea.
So like for me it would be 1/4 on the outside of the house and around the gardens.
Build a deck out of artificial wood so no more staining. As well as build a 3 season room the whole back of house.
Redo all of DH's gardens with cement blocks, native grasses or such for borders.
Tear down his so called shed and build him a proper shed with 2 floors, cement floor and plenty of storage and space for all his tools and garden stuff.
Clean out barn, take down stalls, and cement both sections to make a decent floor as well as set up storage rooms for each member of family so their things are all properly stored. Then put in a bathroom, and make the larger area for garage sales, meet ups or whatever we want it for.
1/4 to go to charities as well as get son a new car, take DH on a dream vacation, get DIL a small space in a rented business park and set up a studio for her to paint and sell her artwork. Plus get DD a condo and moved out.
1/4 for inside of house. New windows, doors, paint most of the rooms, new curtains, new flooring, new washer & dryer, finish the utlity room finally and turn DD old room into room for DH to do what he wants.
Leaving 1/4 to spend on my dolls, get my room the way I want it as well as save some for trips to big BJD conventions.
Now lets see how you spend this much money.