I use a 4-stage approach:

Each family member has a daypack that can provide their minimum shelter, food, water purification, medical needs and other 10 essentials for 3 days in their vehicle.

Each family member also has a duffel bag in their closet that reproduces the daypack but with additional clothing, shelter/insulation and personal protection/tools. Used with the daypack this would provide 6 days worth of food and meds and is small/light enough to carry with the backpack for brief hikes.

I have a large duffel that contains a tent, basic camping gear, better water purification and cooking gear, and 3 additional days food for 3 people. This would only be employed if we could drive off, so it implies that the prior two bags would also be used for up to 9 days of supplies.

Finally I have my pop-up camper that is always stocked with 15 gallons of water (refreshed monthly), 5 days food, 2 changes of clothing, and plenty of other amenities. Obviously, if the opportunity allowed the use of the camper we would throw all the prior kits into the tow rig for a combined two weeks of supplies and quite comfortable living.

The fly in the ointment is that DD lives about 100 miles away at college. So for her to benefit from options 3 and 4 requires meeting-up at a pre-planned rendezvous location. We have identified and visited several locations, even have staged additional materials at a few. But geography doesn't favor a successful rendezvous, particularly if travel by car and public transportation is restricted. So we've also made arrangements for friends and family to provide assistance if the situation doesn't allow us to link-up.

An important factor is to inspect each kit periodically for replenishment. Kids are likely to "borrow" things from their kits and forget to put them back. An easy fix is to wrap the bags in stretch-film designed for wrapping packages to pallets. This way its easier to determine when a kit has been pilfered without performing a full inventory, and it discourages pilfering in the first place. Put a sheet of paper on top of the bag before wrapping to list expiration dates for any perishables and last minute additions that might be required (such as short-life prescriptions and important papers).