@Tim Bradley In a great deal you can get it all back out. In a more realistic deal you might leave some money in. It's all about acquisition price for brrrr. If you get great off market houses you can probably get it all out. MLS is unlikely to provide this in the current market. You need to be all in for ~ 70% of ARV to get all capital out on a 75% refi. The 5% difference accounts for fees, carrying costs, etc beyond just the rehab. Personally I am fine leaving $5-10K in a house because I have the money to allow for it. That would be an issue for someone with limited funds so you have to assess your situation. The rehab could go over budget or the appraisal could come back low, so the potential is there to leave money in the deal even when it looks great on paper during your upfront analysis. Just be prepared for that - hope for the best but plan for the worst.
As far as the seasoning period, you can get around that by using the delayed financing exemption. You can start this refi the day after closing. You can refi 75% or ARV or 100% of HUD. If you want to pull your rehab cost out via delayed financing then just have the rehab bid by your contractor and have the title company add the cost to your HUD. Only do this if you have a solid contractor that you trust to pay up front, as they will be paid directly from closing before doing any work.
Happy to discuss further if you want to PM me.