Multiple s&s ISAs?

[Chicken Chaser]

I set up a S&S ISA a couple of years ago with NatWest. The rate works out about 0.6% so it's not expensive and ive been getting about 8% return over the period. I went for a fairly balanced approach however, I'm now thinking about whether it's worth opening a new one, with the aim of using it in 10 years and going for the full on aggressive win or lose option.
I was originally planning on taking the one I currently have in 10 years but I might extend that to 15 depending on how things pan out.

Is this viable or is there a better way to invest? I'm not maxxing them out each year but I am putting a sizeable chunk in.

[Simpo Two]

You don't need to open a new one, you can keep putting new money - up to £20K a year - into the one you have. You can have 50% 'balanced' and 50% 'aggressive' - it will average out. Or have another one if it helps to keep your head clear. However, don't think of an ISA as something with a time limit, and don't take all the money out and close the account, because you can't get that allowance back.

[Chicken Chaser]

Yeah I know they're not time limited but the plan is not to take out for that period, as my kids will be at an age where I'll probably need to support them heavily financially so it'll be a pot to dip into. I'm looking at it as something which might supplement me going part time before I get my first pension at 60.

[FriedMarsBar]

over that sort of period I'd be looking to ensure you're not overpaying in annual fees, maybe review what you're paying for the fund on your existing provider agains what you'd pay on Vanguard or Hargreaves Lansdown