Condo to Rental - Move to New House - Logistics and Financing ???

[Adam Sharp]

Hi BP - as always, I dont know how to solve my current situation so I am coming to you.

We are ready to move to a bigger house in Seattle and currently own/live in a 750sf condo (HOA below rental cap). In order for me to achieve a killer rate on a new/larger place (and quite frankly qualify at all), I need to have a lease in place on my condo to show that my income to expense ratio is at an acceptable level.

I am having a hard time getting my head around the logistics of making this happen while limiting my exposure and not leaving my family homeless. 

My problem is that I want adequate time to search for a home in a relatively fast moving Seattle market; and will need to close quickly when I do.  However in order to close quickly I will instantly need to have a lease in place for my condo.  There has to be a solution that I am not thinking of and I could really use some help.

The only thing I can come up with is to pack up my condo, list it, lease it, and move into a short term rental.  Once that is complete I can start searching for a new home and try to close as quickly as possible.  This is the only way I can think of reducing my exposure of paying a double mortgage, and securing the rate that i want (along with qualifying to begin with) on the next house.  However it obviously leaves me exposed to what the market has to offer on the next home and I am not sure I want to bear that risk either.  Along with being a logistical nightmare while maintaing a very demanding 10hr/day day-job.

Has anyone ever navigated this before?  Any advice would be greatly appreciated.

Thanks in advance!