As long as the L1/L2 between them is clean and fast that should be OK. You can adjust advbase if it isn't. With a higher advbase it won't fail over as fast, but it is more tolerate of latency between the nodes. Having them in different places in the same building is not unheard of, or even separate buildings on the same campus. It's not ideal but it can work. I think we even had someone try to use CARP for HA to a node in a DC as some attempt at DR, but I can't remember if that ended up working in the end.
When working with skew and base values for CARP VIPs, Skew values are 1/256th of a second, and base values add whole seconds. So if you set advbase to 1, then it would wait 1 second + skew, rather than only the skew time.