Sorry.. if you are a family of five.. you cannot use quad rooms.. Rick Steves tours does have some rooms on the Family tour ( I took my 11 yr old on it years ago.. super fun btw) and there was one family with three kids. In some places they got a room that would take five.. but in others they were put in double and triple rooms.
Do not compare a RS Family tour with any other tour.. they may be cheaper.. but they will not be better for kids.. My dd loved our tour.. it really did work well with the kids.. We had 26 people on our tour.. 14 of whom were kids aged 8-17.. and the kids had a blast.. as the parents.
RS tours are not cheaper then doing it on your own.. but they are easier.. no herding the family from train station to train station or hotel to hotel. .but.. if you want to save money.. instead of doing a tour.. choose 2 or 3 destinations and do them on your own.. London, Amsterdam, Paris and Rome .. mix and match to your tastes are good combos.
Finding hotel rooms for five will always be a huge hassle though.
I had three kids.. and that is why my husband and I decided to do our holidays in Europe differently. A five person holiday can be pricey , two hotel rooms, larger rental car etc.. so we did it this way. I took oldest son when he was 13.. we did London and Paris for 17 days. Then hubby took next oldest son when he was 14 , they did London , Paris and Germany.. 21 days.. then I took our youngest, daughter when she was 11.. we did the Rick Steves Family tour for 14 days.. and I added 12 days.. 7 to Paris where tour ended and 5 to Rome where tour started.
Not for everyone , but we all had a blast. Tour was not an option for one of my sons because he has some issues that make group travel impractical.. and other son wanted to do other things.. but my daughter and I though mixing the tour with independent travel was great.