Well so far both my husband and bf identify as mono so I haven't considered that option.. But I will add it to the things we must discuss. Realistically cohabitation would be at least a year away which gives us lots of planning time. I love to escape to my bf's apartment, but I do miss my kids horribly when they don't come along.
(And of course as soon as I posted my post I found a wonderful thread where Redpepper addresses all of this.)