We contemplated sticking with one but we were both had siblings and felt it was right to have at least 2. 2nd pregnancy didn't go as well as we hoped, a bit of a scare with an emergency c section, but in the end things turned out fine, a lot harder recovery. I think a 3rd kid is out of the question after that experience.
My SIL has only 1 and I can see her life is a lot more free for her to do personal things, but I also feel her daughter is lonely, she always asks us to come over so she can play with her cousin. I see this in a few friends who only have 1 kid. The only child does get a bit lonely and needs a lot more adult interaction. Where as if they had a sibling they would bother you a bit less. Me and my brother basically grew up playing with each other, our parents were mostly busy working so we didn't bother them as much.
Having two can be very tough in the beginning, you need to learn to multi task well. There's no tag teaming with an even ratio, it's all hands on deck. Forget about personal time and you going out for a drink with friends while the other stays home to watch 2 kids. Over time it does get better for some people. You probably will learn to watch 2 on your own but not everyone is able to. I have friends who can barely watch 1 kid let alone 2. Putting 2 kids down for a nap and bedtime is tough on your own.
I also think the age gap can make a big difference, we had 2 under 2, while the smaller age gap is better in the long run as they get older they could play with each other and share in activities, it's tougher in the short run. A 2 year old gets jealous and has terrible tantrums at 2, all while you're dealing with an infant. It might have been easier if we waited until the oldest was at least 3 so he can communicate with us and he'd be a bit more independent by then. But with the oldest being only 20 months when we had are 2nd baby it was hard to know what the toddler wanted. Now my kids are 3 and 1 and things are a lot smoother, but the initial year was tough.
2 bed rooms is a non issue. I grew up in a 2 bedroom sharing with my sibling and we currently live in a 2 bedroom with 2 kids, the older one sleeps with us. The younger one we trained to sleep in his own room so he doesn't get woken up by his energetic toddler brother. In the future when they're both older we'll put them together to share a room.
I also wouldn't make any decisions based on money either unless you're in poverty and can barely put food on the table. 2nd kid doesn't cost a whole lot more since you can hand down most things, we hardly buy anything new for the 2nd kid. The biggest cost would be child care, but that's for a limited time.
I agree with everyone else working 2 50+hr a week jobs with 2 kids is a bad idea, someone needs to cut back or you may need a full time nanny if you don't have help from family. I see it with some friends I have they're stressed to the max. Racing between work and daycare each morning and evening with little sleep, by the time they both get home from work and put dinner on the table it's time for bed for the kids and back to doing it all over again in the morning and pray your kids slept decently during the night. That leaves you with just weekends and most of that will be used to run errands, shopping and take care of other things. I wouldn't have the extra kids if long hours at work was non negotiable.