What am I missing in weighing the benefits of downsizing my home before kids go to college?

Hey everyone I have a pretty important question to ask regarding finances. Situation is:

*I have two 15 year old kids going to college in two years…one most likely on academic/athletic scholarship and one using reciprocity perk from work.

*current home is worth about a million bucks, but I have projected repairs of nearly $100k over the next 5-6 years (roof, driveway, windows, etc.). Most likely will sell for about $950k.

*Idea is to sell now and downsize to newer construction. Not as nice of a neighborhood, but still amazing. Not worried about resale value due to the crazy market we have in our area. Plan to be here another 10-20 years. New house is about $600k.

*Will pocket and utilize small loan to have about $250k in liquid assets. Idea is to invest this now. I am in Oregon, married, and 44…. It sure how much I am going to get hit with capital gains. Also closing costs, etc.

*Even with loan, my wife and I will be bringing home an additional $2500k a month after all bills and retirement paid into since we don’t have a $3500 mortgage.

*In this new house we lose garage space but no living space, get a way better living area, and no crazy 40 degree slope driveway 🙂.

I have 20-25 more years of work, and we figure this plan gives us much more flexibility for the unknown as our savings is very minor compared to our retirement and other investments we really shouldn’t touch.

Just need some folks smarter in finance than I am for an opinion.

TLDR: Selling house to reduce monthly payments, increase liquid assets and prep for kids’ college…missing anything?