My Xbox Live Gold subscription is scheduled to renew next month. If I were to cancel it,...

Hmm...over priced? 4 free games a month, discounts on other games through Deals with Gold.

$60 a year in the US for 12 months but I got it on sale for $42.

Xbox Live Gold subscription changes FAQ

As of 18 February 2016, the price of Xbox Live subscriptions will be increasing. If your subscription is currently set to renew automatically before 18 February 2016, you’ll be charged the current price at the time of your next scheduled auto renewal. If
your subscription is currently set to renew automatically after 18 February 2016, you’ll be charged the new price at the time of your next scheduled auto renewal.

https://support.xbox.com/en-HK/billing/xbox-subscriptions/gold-subscription-changes-faq

"Membership continues to be charged at the then-current price (subject to change; plus applicable taxes) unless cancelled. Cancel any time to stop your next scheduled charge; …"

This statement confirms that GP Ultimate is considered a separate subscription, one that can be cancelled prior to the next scheduled payment. If prepaid codes have been redeemed, that next payment won't be until those converted months are consumed.
Referring back to the previous example, if you decided GP Ultimate wasn't for you, you would need to cancel (or disable auto-renew) prior to 1 August 2019. After that, you could then just purchase Gold, if that's all you wanted. But I believe it is clear that
you can indeed go back to standard subscriptions if you don't like Ultimate, but that can only be after converted Ultimate months are consumed. I do hope this helps ...

This. ^ It's just like if you were to cancel a gold subscription. Your account reverts to a free/silver account with none of those benefits. If you cancel (or don't renew) your Ultimate Game Pass, your account will revert to a free/silver account and you
will no longer have game pass. So you would only have what you decide to purchase next. If you just want gold, then you just buy a gold subscription. It will stay gold unless you decide to upgrade to Ultimate again.

Since your current gold would be upgraded, you wouldn't have Ultimate for just 1 month, you would have Ultimate for 13 months. The Ultimate subscription would not end once the 1st month is over. It would not be scheduled to end or renew for 13 months.
So even if you didn't want to keep the game pass portion of the subscription, the best thing to do would be to turn off auto-renewal and keep the remainder of the subscription. If you cancel Ultimate before the 13 months is over, it will cancel gold as well
since that is included in the subscription and you would have to purchase a new gold subscription.

Online multiplayer works on games that are free though they it’s only games that cost money where online multiplayer won’t work I have friends that play fortnite and apex legends without a active subscription rogue company is another game they made this change a couple months ago List of games that don’t require Xbox live gold

You would lose games with gold, deals and access to online gaming on games that cost money but games that are free you’d be able to access multiplayer still games like apex legends fortnite halo infinite and I believe cod warzone you’ll still be able to access party chats but a game like cod vanguard and Cold Wars standard multiplayer you can’t play without the membership