You should never be using the whole 80 card deck. The 16 card 'recommended for first play' deck are 4 cards per season (specifically the ones with the junimo in the corner). For normal play you should be randomly selecting 4 cards for each season from the 80 card deck.
So the 16 'starter' season cards should already be easier since they provide reliability. There's no official alternate game that includes having more than 4 season cards per season but if you want it a little easier then sure, maybe add 1 per season.
If you want to play the 16 card way then as the above comment, there's recommendations of reducing the goals. If you had the Mines grandpa goal when you struggled, just removing that card from the options might help. It's particularly difficult with less players as it doesn't scale.
Really I think the game is balanced well for a tight game which gets easier as you retry, but if it's too tight a game for you messing with the goals and bundles should be enough to give you most of the experience with a little less stress :)