I just have one, DH works a lot of weekends and we both work full time. Very little time to re-charge. A few hours to yourself makes the world of difference.
The day came, like a break in the clouds, when I realized I had quite enjoyed DS company.
Once we could just set off out for the day without military precision planning, stop for a bite wherever, eat something off the menu without a fuss, go to a normal toilet without a fuss, walk along chatting and hold my hand to cross the road, the fog started to clear. Still the odd challenging day but exhausting became less the norm. And then they start entertaining themselves for longer stretches, scooting along while you chat to DH/a pal. You get some head space.
I do remember getting to the weekend and wondering why I'd been looking forward to it. Arranging to meet other families/parents can help. Sometimes a larger number of children is actually less work, as they entertain each other. Toys never normally played with are somehow more fun when a different kid is around.
Also getting out to a child friendly destination. Season ticket to somewhere nearby where you can have a walk in the fresh air, sit down for a brew and ideally there's a playframe or similar close to the café. Money well spent if you can spare it. Couldn't care less if it's a zoo, castle or garden, I'm having a brew and sitting down while the kid blows off some steam. And we're out the house.
Also as they get older you can get them into regular activities. DS does drama for 2.5 hours Saturday mornings. I get a couple of hours to myself guaranteed and he always seems more settled afterwards. Even if you have to stay at the venue (e.g. swimming) I find having the routine helps get the weekend off to a good start, so if you can manage the likes of swimming as a regular weekend activity it can kind of help see you through the weekend.
Really no longer bothered by DH working three weekends in a row.