The house has been on the market but traffic is slow - not sure if this is due to the current environment or something specific I should address within my listing (we've already adjusted the price). 

Quote from @Maggie Hamill: I believe the earliest date you can use is the day it was marketed as available, but I'm not an expert.

Given the high interest rates and the need for additional cash, it might be better to wait until market conditions improve.

This is often a losing proposition for the seller, unfortunately.Granted - when a house in in disrepair and would be hard to market otherwise, it is a path forward for the seller.  

Hello, dear fellow investors,I am considering relocating from Northampton, MA to Denver, CO, and would like to get a feel for how the Fix+Flip market works there.

One city is seeing the market at work.

That's usually because they're not selling their loan on the secondary market. 

I'm in the small multifamily market.  

It can be a more stable rental.It depends upon what you think commercial market value is.

I'd find off-market deals, do some cosmetic updates, and then refinance.