What's the layout of your house? What areas are underutilized now and which areas are straining at the seams? You could post in the real estate forum and we could help you figure out how to maximize your space.

I'm in a similar boat re: interest rates. My rate is low, which is great, but it'll suck if I ever have to move for some reason - I won't be able to buy as much house. (I have a SFH in Arlington and would only move if I got a dream job too far away to commute.)

I miss my previous townhouse sometimes. The lawn is actually a pain in the ass that we literally almost never use. We spent more time in our tiny townhouse backyard and deck. We had nicer bathrooms in our old house, and a LOT more closet space. And when it is windy out, it is so loud. The interior townhouse really shielded you from the wind. (which can affect your heating bills.) Plus when things break, they cost more - a new roof will be at least 3x more expensive for this house.