You can look at mesh networks to make it so that the wifi network handoff is seamless. The routers will communicate to each other and ensure that traffic flows smoothly by making one the DHCP server automatically. You may need a switch in the middle to split the connection to both ends.
The Google OnHub routers are a good budget product vs. Ubiquiti or Orbi, as they are on sale for a good price:
TP-Link OnHub AC1900 TGR1900BLK TGR1900 Wireles Router $89.99 is a good deal.
However, I am skeptical that one router (a good one, such as a Netgear Nighthawk or similar) cannot cover a condo. My parent's 4000 sqft house is covered nicely by a Nighthawk on all floors.