Will a Super Kingsize Ziplink mattress fit up my staircase?

Our stairs come down into a hall with a door into a utility room offset to the stairs across a 3ft gap. The door is not very usefully only 6 foot three tall. There's a newell post to negotiate as well. We want a super king size base, but by just looking its clear a single base unit won't negotiate the space. But I hope a zip and link would (we've bought these from you before for a different house... Can you help with the measurements that we'd need to take to ensure we have enough clearance to get zip and link super kingsize around and up the stairs please?
P.s. If they did not fit, could be take them through an upstairs window, or would health and safety not allow that?
Many thanks