I've mixed 2 yards of soil in my basement before, it's more of a question of how much space you have imo. You can use like 35-50 gallon garbage cans or buy a couple of like 50-100 gallon fabric pots and mix in those as well instead of a tarp then just keep watering the pot to keep it moist, wrap some shipping plastic/Saran wrap around the outside and leave about 3-4 inches on the bottom and it'll stay moist much longer as well. Personally I think the large pots are easier but whatever works best for your situation should be fine.
Edit:just noticed you don't have a basement, you should still be fine, 100gallons of soil will heat up for probably about a week (I made ~200 gallons a couple months ago and it got to 120-130ish for like 4 days.) but I've never had it raise the temps in my area significantly, it will make a lot of humidity and offgas a little as it's cooking though. Probably nothing a cracked window and a small fan couldn't take care of though.