Another possibility is to change the shape of the firepit. A longer rectangle with rounded corners would look very nice.
My favorite ideas are Kim's - move it closer to the spa making for a very nice conversation area, or get a portable firepit. That's actually what we have for a patio table - a firepit from Lowe's with a round patio table top sitting on it. It looks very nice and gives more of a coffee table feel for conversation. Little ones sit more comfortably at it. And we can move it when needed. We don't use it as a firepit, but in your case, you would have a firepit for the cooler months and an outdoor casual conversation table for the hotter months. That would give you the versatility of repurposing it for different occasions.
One more thought on a different shape if you want the permanent firepit is this : (can't think of the shape name...) Take a rectangular strip but curve it like the letter 'C' but not as closed. Or think of it like the curved bench I've seen people pour on the backside of their round fire pit. Then.... place it a few feet behind the spa to sort of echo the shape of the spa. It wouldn't take as much space as a round firepit. I think the curved look of the flames would be very pretty and unique. I'll see if I can find one on Pinterest.
My favorite ideas are Kim's - move it closer to the spa making for a very nice conversation area, or get a portable firepit. That's actually what we have for a patio table - a firepit from Lowe's with a round patio table top sitting on it. It looks very nice and gives more of a coffee table feel for conversation. Little ones sit more comfortably at it. And we can move it when needed. We don't use it as a firepit, but in your case, you would have a firepit for the cooler months and an outdoor casual conversation table for the hotter months. That would give you the versatility of repurposing it for different occasions.
One more thought on a different shape if you want the permanent firepit is this : (can't think of the shape name...) Take a rectangular strip but curve it like the letter 'C' but not as closed. Or think of it like the curved bench I've seen people pour on the backside of their round fire pit. Then.... place it a few feet behind the spa to sort of echo the shape of the spa. It wouldn't take as much space as a round firepit. I think the curved look of the flames would be very pretty and unique. I'll see if I can find one on Pinterest.