For background, we sold our house last September; and reserved an off-plan new build. So far, it’s been delay after delay. I have DC2 due end of March, house isn’t set to be ready until ‘mid-March’ but we’ve not actually been given anything more specific than that since the beginning of December. We have been chasing but no one replied to us. How likely is it that our house will be delayed further? We went for a nosey last weekend and the house looks ‘done’ from the outside.. but the houses next to are still covered in scaffolding and haven’t been bricked/painted yet. - the road is covered in materials, and the garden is probably a 10ft pile of mug that obviously needs removing, levelling then fences up, grass down ect. It just seems like next month isn’t realistic.
Our issue is, we’re essentially homeless from the end of March. We’ve managed to find a temporary accommodation through my step father, but they need the house back from April. There is nothing to rent, holiday accommodation is extortionately priced and we just can’t afford it, family’s houses are overcrowded as it is and the only person we can possibly live with is my dad who is a indoor chain-smoker and struggles with remembering to go outside - so I don’t want to live with him with my toddler and newborn, it’s not only a SIDS risk just having the smoke around, but also after just going for tea we all come away absolutely feeling of smoke, I don’t want this on my kids clothes, beds ect.
Moving on- our house sale:
How long do we get on average to exchange, complete and move out/hand the keys in? We’re waiting to hear about dates which should be this week.. probably next week now as they don’t work weekends. - but we really can’t afford to lose the sale and it’s getting on for 5/6 months since the offer was made, this is due to their solicitor being very slow and wasn’t ready with paperwork, and we’ve made it clear that we’re not waiting on our house being ready and will find temp accommodation (we just can’t lose this sale otherwise we’d be more negotiating) - but does anyone know what they’ll expect in terms of how long they’ll give us to pack up and get out? 1week? 3 weeks? We’re hoping that it’s going to be at least the 25th Feb as that’s when our temp house can be used from but I’m starting to get nervous that we’re gonna be asked to hand in the keys next week 
Also, is it rude/frowned upon to contact the buyers directly? They’re a local brother and sister who are buying to rent and I keep wanting to ‘bump’ into them in town so I can bring up to them what they’re expectations are. I feel like being able to chat freely with them about our situation and that we’re not trying to drag it out would be better than whatever communication their getting through our solicitors? Is that a bad thing to do?