I'd appreciate some input/advice about the likelihood of upper bin space being available for a couple upcoming flights, SMF-DEN-DCA and return. I haven't flown Frontier before and have been told that it's probably easier to find room for my business-size roller (17" x 15") if we sit near the back of the plane. On the last 2 flights we took on UA, the GA announced that all rollers had to be checked at the gate and would not be allowed on the plane, due to lack of space. This would not work for us since the bag will contain our laptop and other valuables we don't want to be separated from. Carrying a separate laptop bag wouldn't work in our case either.

I realize every flight is different, but if there are some common trends, my questions are:

1) Is it very common for passengers to be required to check carry-ons that won't fit under the seats?

2) Will sitting near the back of the plane make it a lot easier to find upper bin space for 1 roller?

Thanks in advance for any help.