are there enough beds for you all? ie a double in each room and a sofa bed? If not enough beds, don't do it! If enough beds, and you think you'll be able to get out often enough to be on top of each other all day aswell, go for it. We maxed out a (CP) house with 2 adults in each double, and a cot in each room. It was fine because we were out most of the days, and just used it to sleep and eat in.
We have 7 people in our teenytiny foldy caravan thing on a regular basis. Granted, four are children and one's a baby, but all the same... And that's only got one room, essentially. You'll be fine- a 3 bed mobile home is a veritable palace!