HELOC Help and Advice

Looking for some Advice and Pros/Cons to a HELOC.

My wife and I have items we definitely want to do now and some that may come up later. Main one now is getting a Generator put in (like a Generac) due to losing power pretty frequently. We have about 300k in Equity in our 600k house.

Spoke with my bank about this and they do fixed rate and variable rates on their HELOC with 10 year draw and up to 30 year payback period.

Mainly my question would be, would it be smart to get the HELOC, take out roughly 25k to do the items we want to do in the short term and set the repayment period to be 30 years so the monthlys are low and then put down lump sum payment once per year?

So, say the monthly is $100 for 25k draw (just throwing random numbers out), we would want to pay that and then pay 5k once a year and have the loan paid off within 4-5 years so we do not accrue that much interest.

We are capable of paying all up front but thats a good chunk of change that we dont love the idea of paying at once. I think we would benefit from taking the small interest hit to pay smaller chunks over a couple years, am I thinking about this all wrong?