I bought a Case 75C and kept my L3130…. For mowing or big open or heavy or cold work, I like it a lot. But the L3130 still gets used a lot for smaller stuff that is tight to do. Can’t imagine not having the l3130…
Kubota B8200, then a Kubota L3130 HST, now a Kubota L3400 HST
I had a L3130 for a couple of years, and it was (still is, I imagine) a good tractor, but as you have said, it lacks power. Okay for a lot of stuff, but even then, it tends to be slower than a more powerful machine would be. I'd suggest going bigger rather than getting something that is only a marginal improvement. Should be several Kubotas that don't have a much bigger footprint than your L3130, yet have twice the ability.
This is my experience, so take it for what it's worth:
Back in 2007, I found my L3010 wasn't quite strong enough to handle some new tasks around my 25 acre spread so I traded it for an L3430 HST. The extra 3 HP helped but it wasn't long before I wished I'd gone bigger. I used the L3430 until 2015 when I again decided I needed something more powerful. Like you, I was concerned about size and tight clearance maneuverability.
The next logical step was the L4060 but it was a larger machine with only 6 added HP. Having learned my lesson with the 3010 to 3430 trade, I decided on the L6060 HSTC. Yeah, it's a bigger tractor physically but I was pleasantly surprised how maneuverable it was. I can get it into most of the places I used the 3010 and 3430. It has all the power I need and the cab is great for working in inclement weather.