I'd say your proposed bottom (leg) layering is too much for the temperature. Thinner layers are better. If the "bib" is a ski bib with insulation, then it will be more than enough with nothing else. Frankly, medium cycling tights with a wind shell would be sufficient.

IMO Wind protection is the most effective part of your layered clothing. I wear my rain pants and rain jacket, but any outer "shell" will do the trick.

As someone else mentioned 25-30F is much warmer than you think, and a mile into the ride you will warm up.

For these temps I wear a medium weight polar fleece up top with my rain shell over it - that's it. I wear a thin skullcap under my helmet to cover my ears and hold heat in, medium weight gloves - something that you might wear on a warm ski day. Legs - thin to medium weight tights (long underwear will work too) and rain pants over that. Hiking socks and my regular MTB shoes. With that, I am perfect by the time my body is warmed up.
The rule of thumb is that it is good to start out a little chilly, knowing that you'll heat up.

If you are on a budget, look into second hand hiking/ski clothing for your outer layers - preferably gore tex "shell" with no insulation. For mid layers, polar fleece works wonderfully well.

I don't typically don my balaclava (face/neck/head) - also a thin piece - until the temps are closer to 20, and below 15 degrees I add a windstopper neck gaitor, a second (thin) base layer up top, and backcountry ski gloves.

Good luck!

Good luck!