Playing zombicide not as a single mission, but as a campaign, consisting of 4 turns that have both an exploration and a siege phase, where zombies try to break your camp.
Using my mission generator (https://udos3dworld.com/ZombicideMissionGenerator/), you can select “Encircle in Street Zones to create suitable maps.
Models that could be used as the evil scientist:
https://www.thingiverse.com/thing:4261954
https://www.thingiverse.com/thing:4048257
https://www.thingiverse.com/thing:6132857